i bought a 5770 for a old machine i use to play games (i can play l4d2 and all the games at 1080p, with all the settings to the max, crysis in high quality). It's a cool graphic videocard, but too many problems with drivers, i was sick of so many "grey banded screens" that frozens the computer. With the newest drivers, In modo it's a shit for selections, ages to select a few polygons in a typical model of mine. With the vendor driver i had crashes, windows restarts, blue screens and grey screens all the time, and just moving the mouse.
For work, it's better a nvidia (although is more expensive). Better drivers and better perfomance in apps. With nvidia we can have things like octane renderer, an unbiased renderer similar to Maxwell but in almost realtime.
The 5xxx series have too many issues with drivers, just check out http://blogs.amd.com/play/
and read the comments. I'm very dissapointed with Ati, but i can't complain, i bought a cheap videocard with good perfomance, for 1/3 of what i needed to pay for a nvidia. With catalyst 10.5 i'm fine but i wish to have the perfomance of the vendor driver without crashes.
It's a pity all the thing about ati drivers.