If i can get 60fps games instead of 30 with the same 1080p resolution id be happy to upgrade tbh. Alot of people dont care about it, but for me it's a night and day diffrence in enjoyment.
framerate bumps require CPU as well as GPU. Some games that are unlocked and nearly hit 60 might be a solid 60, but I don't expect that is the route most will take. The GPU is disproportionately more improved so you'll be much more likely to see higher resolutions, higher shadow detail etc. Literally the kinds of things you'd expect to see on a PC game when going from a 7850 to a 290 but keeping the same CPU