B4ttleCat

REJOICE! 1.8.1 finally fixes this issue, boys and girls! 
...
Just kidding. As you were.

I agree but it seems the importance is not understood. It's been 4 years since the first post.

At least I'm not the only one that is frustrated by this I guess. Apparently the Serif crew does not see this as a priority which is sad. I personally would rather have Select Same within Designer, than the entire Publisher app.
Client: "Can you make the stroke a little thicker on this clipart?"
Me using Designer: "Sure, I can do that. Just give me about 5 or 6 hours."
Also me using Designer (2 hours in): Damnit! I clicked a blank spot accidentally! Now I have to start selecting all over again.
Me using Illustrator: I just increased the stroke on all 652 objects while you were blinking.

Personally, I was much more anxious for the release of Publisher. But that's now been quite some time. 
This feature really shouldn't be a big deal to implement. At least in a basic way that would be good enough for those of us asking for it. I suspect that Serif are wanting to blow the roof off with a product defining implementation of it or something. But if that's the case, I really just wish they would do something as a stop gap.
Unless of course this is true:
 

All the reasons for not being more up front about things come back to the idea that their customers are really stupid. That’s not a great look. 
 
From my experience, you tell people honestly and thoughtfully what is going on, why something is happening or not and they are pretty good about Understanding it. 
What people absolutely abhor, is being managed like small children, especially when they are putting in quite a lot of time and effort to assist with the discovery and squashing of bugs. 

That seems to be an important point. Even though these forums are very active I have the impression that only a minority of the actual users of Affinity software are even aware that these exist. Nor do they care to participate (and that of course is totally OK).
OTOH some of the most requested (and discussed) features are also obviously (?) some of the most missing features 
d.

I would say the purpose for many users is defeated. It is like having a text editor without a find command. Essentially useless for many people.
For us, it is the primary use for a vector art editor. We produce drawings in CAD and then often edit the PDFs for presentation purposes. Our files therefore have 000s of objects, many of which have the same style. Selecting all manually is a non-starter.

Not sure how this is any way relevant to my point.

So...someone above suggested alternatives, one of which was VectorStyler. I downloaded the beta (it's only in beta now), and opened a PDF exported from AutoCAD. I did Select All, to rotate from portrait to landscape. VectorStyler crashed. I re-opened it, and there was a crash-report dialog. I filled it out and sent it. Almost immediately came an email, asking if I would send the offending PDF. I did so. The next morning, I got an email indicating that there was a new beta version, which should solve the problem, would I try it. Problem solved!
This is how customer support is supposed to work.

Yep, sadly it doesn’t take long before this becomes an insurmountable issue. It’s fundamental to vector illustration. 

Switched to Affinity Designer after a decade of Illustrator and it took me less than an hour before my troubleshooting search found this thread. I'm completely stuck without "select same" functionality... will ask for a refund given how unresponsive Serif seems to be for such a critical feature request.
Pop! (this is the sound of my initial enthusiasm for Affinity Designer disappearing)

It was mainly rhetorical, picking up the point from @Mark Ingram about how we've had years of free updates.  This is a common argument made but is more whattaboutery than an actual answer. If they feel hard done by for providing free updates, or for that matter, feel like it exempts them from criticism then I think it is really rather misguided.
I was trying to make the point that a) we don't get to choose or not whether updates are free or not and, b) that I and many others would happily to get an update that includes this feature.
I will continue to wait with my wallet at the ready if needed.

Yet it is quite literally, better than nothing which is where we are at and have been for quite some time

I'm intrigued by your definition of straight away. Is it measured in decades?

Where and how do I pay to get this feature added?

No denying that.  Well, on the bright side, if you're young enough you might actually see some of these critical features before you retire.  Maybe.

If you’ve only recently bought it, I would go for the refund. You’re likely to get that whereas a comment from Serif on when this feature will be implemented is... well... incredibly unlikely based on the evidence of this very long discussion.
I’ve come to the assumption that there must be a fundamental flaw in the way they’ve implemented the apps to date which precludes the implementation of this feature. Otherwise, why the hell wouldn’t they have done it years ago. At this point many of us would probably settle for a commitment that it will come with 2.0 and have to pay again for it. At least we would then know!

I had to agree with some of this. I am wondering if the multi platform model is diluting the strength of each product.
Such fracterising may be having an impact on features like this. Which as you hinted at, could possibly be solved if they would simply open the app up via APIs so we could have everything as a plugin.

I love Affinity Designer and the great wonderful people behind it. I'm an early adopter and devised many of my studio's workflows around it. To the point that when a client requests a 'last-minute' change in the style guides I don't hesitate in assigning an intern, when there's one around, just to go through the time consuming and the painstaking chore of changing all the objects that need to be changed. Some of our projects can be huge. We have teams of designers and illustrators working on year-long projects that generate hundreds of artwork crammed artboards. I don't even get the chance to open all those files. Now, when the client requests us something seemingly simple as: "guys, the school computers have really bad screens. We need to increase the line thickness a bit". That makes my stomach drop. In many projects that means entire days of grunt work. Unhappiness ensues. Interns blame their fate. The less organized creatives become scapegoats for not keeping their layers in order. I struggle to outsource this burden and keep this evil out of the door. Sites like Mechanical Turk is not an option because very few users know of Affinity. Most often I end up hiring a freelancer, buying them an Affinity Designer copy, teach them the ropes in 15 minutes, pat them in the back and hope for the best. The only reason I endure this is just that I am a data freak and I measure everything: Affinity is so good that the performance gain is still worth this pain. But... guys, honestly, it's about time we have a Select Same [property] feature. Don't know any producer, project manager, director or anyone who has the responsibility to deliver work to clients who I have shown Affinity to that haven't scoffed at this omission. Let's be frank about what 'software reliability' means to an agency or studio: the features to implement that $%#! last-minute infuriating client change request without missing the deadline or derailing the budget. The reason why I don't understand why this feature is not a priority is that, as not only a creative but also as a business owner, I tend to consider anything that causes loss of productivity and eventually money, a priority. And honestly, I'd really love to be able to convince my clients to adopt Affinity Designer too so I don't have to go through the other—and last—grievance I have: conversion to Illustrator. I really dream about the day clients stop to ask me to convert the source files to AI. Please, let's make this happen. I really love the tool and admire your work but can't hold this back anymore. I think it's about time I share this.

Hey guys,
 
I hope I haven't missed something in the UI but basically I'm after a "lock transparency" feature that works the same way as in PS. It's very handy for blurring things that you don't want the edges to shrink/grow. It also has the secondary benefit of being able to paint inside already painted pixels without going outside the bounds. (I know this can be done by masking, but locking transparency may be the workflow of many already and means you don't have to create an extra layer to mask with).

What has this thread become, oh my...
I think the original purpose is really mudded at this point, with free etymology- to Adobe history classes, whereas it is pretty clear: as a decent vector drawing package, a lot of users (myself included) are either
- getting the base linework from someone else (a client sends it to you, or it is provided by the government, or a consultant firm, the possibilities are endless)
- are doing other stuff as a living (architects, urban planners, data scientists, etc.), and create the linework in another application(s) (CAD, BIM, GIS, etc.), which they would want to recolour, restyle, etc., to fit the branding of the project for example
so we need a system to sort the often tens or hundreds of thousands of random objects to be able to apply global colours, groups, folders, <any other relevant Designer feature>, to work with them, because Designer is a good illustration software, that's why we are here at the end...
Right now, this is basically impossible. Let me rephrase, so time consuming, that it is not financially/time-wise feasible.
That's it. 
I honestly don't get why this is a "pet-feature" to anyone...
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 [~off-topic]
A lot of people mentioned other use cases, other software for inspiration, e.g. I've provided another example how it is done outside the Adobe ecosystem (ARCHICAD) in an extremely robust and simple way, to illustrate that it is the idea of doing batch selections for sorting that matters. If Serif comes up with a unique system, I'm all happy. Not having anything is really sad and extremely counter-productive on the other hand.
What I find sad too, is the indefinite state they let the users in. In two weeks we could grab a beer and celebrate the 5th anniversary of this thread. Still, the moderator only can say what he did when Publisher was pushed back again and again and again and again and...: it's done when it's done. As others, I'm in the construction industry too, where scope, budget, and deadline are fixed things. I also do scripts for automation and custom objects for our workflow, so I think I have a vague understanding how software development differs in these terms (scope, budget, deadline). What I don't understand is the lack of transparency - we can debate about this later, whether it is the appropriate phrasing of my thoughts in English, but it a simple question: is this/a similar feature or a set of features coming that fulfil the initial request , or not? It's binary to me: yes/no. No? Fine, I won't bother this thread anymore, and continue using Photo and Publisher. I get, that you won't give us further information, you've made that clear thousands of times, but not answering a simple yes/no to these ones are just getting ridiculous at this point. 
To me two good examples of how to manage expectations and requests are McNeel with the Rhino forum (I can see a few user names from Discourse here, they can agree/disagree) and the Corona dev team (former Render Legion, now Chaos I think). The Corona development has an open Trello roadmap here for example: https://trello.com/b/dgI8vjDb/corona-road-map-cinema-4d I find both situation really-really comforting, knowing that they do listen (yeah, there are issues there too, of course).
As someone who bought the complete suite, I honestly don't like the way Serif treats user requests (specifically this one), but that's my problem I guess, which I can manage.
What I consider disturbing on the other hand is the hostility of the "100% satisfied" users towards this very reasonable request and the people voicing their concerns.
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Posting to +1 to keep letting Serif know that lack of this feature is a deal-breaker for full adaption of A.D. Seems like Serif got so into building other apps (Photo, Publisher, iOS apps, etc.) they forgot to finish Designer. A shame. 

Hard, hard agree. I've long given up on ever using this software again. At this point, it's the principle. I tell everyone I can about this absurd story of the simple feature that never was. I'm only subscribed to the thread to see how far it goes. Cheers, everyone!

Well, be reasonable. Compare Designer panels and features to Illustrator, implementation and ux, and you will instantly get where the inspiration came from. Same for Photo/Photoshop and Publisher/InDesign. Should I start posting screenshots to compare?
Just one little example:
-vs-
Nobody said it's a copy. Well...
But back to the topic: to make that switch, we need some features the other one has. If there was no issue implementing Unsharp Mask filter exactly the same way as it's for decades in Photoshop, why should such a little feature as Select by... should be treated in a different way?
And this very feature, Select by attribute, is present even in the free Inkscape product. So just take inspiration there (if you hate Illustrator comparison that much).
People are looking for Adobe product alternatives. Alternative product has to offer similar features so you could be able to switch without breaking your workflow too much. If Serif comes with another solution, awesome. But for 5 years since this topic started, there is no other, but manual solution to this very existing problem. See usercases from this very thread. It's not just a marginal feature request.
 

And what percentage of those new customers find themselves in the same boat as many others here - that they now have purchased a product which is unusable in many projects for which they purchased it? Increased purchases does not equal active users.
This is my circumstance: I cannot use AD for many of my projects just for this missing feature. And having no commitment - or even recognition of its inclusion on the timeline -  from the developers for the implementation of this (most requested) feature makes me unwilling to put in the effort to learn a new software package, when I may never be able to utilize it fully. 
My hope, and that of many others here, is to avoid the Adobe extortion/rental situation. Sadly, AD is not the solution to that.