I've MSI r9 270x , and I can play watch dogs at 1080p ULTRA and get fps around 30~40 with a little stuttering at times.
The temperature goes up to 65°c~70°c after 4-5 hours of continuous gaming.[ Room temperature : 38~35°c].
I also played BF-4 and Far Cry 4, and had a little stuttering but had good FPS though.
I would recommend very high setting for smoother play. There's not much difference anyway.