Congrats on launching v1.5. I love Affinity Designer's speed and vector tools. It's always open on the side when I'm designing UI with sketch to do quick vector work, then bring it back to Sketch.
Now that you guys brought art boards, constraints, styles, etc... to Affinity, I'm very happy to consider using Affinity Designer exclusively (it's just faster than sketch!)
But in order to get to that point and make it the perfect vector + interface tool, there needs to be a couple of things:
1. Artboard on phone live preview. Like Sketch Mirror, seeing my design as a final user—on the phone—is crucial.
2. Content generation: Be able to say, fill a bunch of shapes with images properly cropped and fitted (for avatars, for example). Generating text is also important for UI design. Currently I use Sketch plugins for this.
3. Grids: Be able to copy a shape a number of times within a user-defined grid of x columns and y rows
4. Scale: enlarging a symbol or group of shapes inside Affinity feels a big buggy and doesn't scale well. I'd like to see a scale feature where I define the dimensions for a group of shapes and it'll grow it proportionally (all styles and effects are scaled as well).
Now, I know everything I've posted is is not trivial at all to build. Having said that, if UI design is a space you guys want to compete in, then I'd really love to see you guys push it further. You're really a few features away from getting designers like me to recommend Affinity exclusively for design work (both designer and photo).
Cheers and congrats on the work guys! Love the new update!