I have Trinity hardware (7660G on the APU + 7670M dGPU). Dota 2 with Catalyst would have some strange FPS issue (FPS would gradually climb up to around 60, then gradually drop to single-digit, and repeat). So it was stuttering, but gracefully (basically it was speedup, slowmo, speedup, slowmo, and in regular intervals).
With radeon, FPS would just be low, like 10-20. No stuttering, but still unplayable. Didn't matter if I used the APU or dGPU.
Windows however, Dota 2's FPS was 60+ most of the time without any real issue.