I've just found about about and bought Affinity Designer. I've been using serif programmes for a couple of decades - I didn't actually realise 'til I read it above that they are abandoning the Plus series. I produce(d) exam papers for an exam board, newsletters and pamphlets and websites for a Parish Council and a construction business and some techy manuals (high graphics content) for a small user base. I'm not a pro but I'm not a dabbler either. So I hope it's OK if I offer my thoughts here. :)
In terms of the grumbles about having to wait for the new affinity suite, if you are using the older Serif programmes then they will actually still work ... I guess I'll stick with the X9 versions of Draw/Paint/Publisher/Web until the Affinity set is complete and then transfer over. I bought Affinity thinking it was going to complement DrawPlus but it appears it's going to replace it, so I'll spend some time seeing how they are similar and how they differ and whether X9 programmes will see me out.
An alternative to releasing Affinity programmes as they are completed is to sit on them until they are all ready. Serif would lose (oodles) of money, we would lose access to programmes that are ready and the inevitable final debugging would be horrendous for a complete suite released all at once. It's the real world so I guess we just have to suck it up. ;)