Hey mate,
I purchased 2 x R9 290's and I've had nothing but trouble with them. Terrible FPS in games, having to set to low to get anything playable, yellow flickering throughout my gameplay that I can't fix. I've tried enabling vsync and also turning vertical refresh on always didn't seem to make a difference. I've tried different types of drivers and noone seems to be able to give me an answer that helps.
I'd suggest steer clear.