I have a 290x with an FX-6350. I wouldn't trade it for the world. Everything just works great. I played the doom demo and it ran very nicely. Sorry I can't be more specific, it's been a while.
If you're moving from a 750 you might need a better Power supply.
Also keep in mind.. if you do get this, uninstall the Nvidia drivers with Display Driver Uninstaller BEFORE you remove the Nvidia card.
Shut down, swap cards and restart.
Install latest AMD driver.