actually AMD FX 83XX should perform at the same level as an i5, except on programs that require strong single core computing, where it is Intel hands down.
I have it and I had no problem with it, it is not that hot with a proper cooler, although it is strange that at 60 degree it gets unstable, whereas Intel is still fine....
but yeah, FX X1XX series was really bad, I have heard about it...
Edit: BTW I just read that for Ocolus Rift it is highly recommended to play titles @1080p over 75 FPS....
We will need brutal hardware for that, or lower the settings