Purchased this to replace the i5-3570K in my girlfriend's PC.
I've had it clocked at 4.8GHz for the last 5+ years, and it's been rock-solid, under 60C load with a Noctua NH-U14S. Perfect 4x Core CPU.
But I wanted to upgrade her PC without upgrading everything else, so I went with the best Z77 CPU - the i7-3770K.
Works great!
I'm a bit disappointed that it doesn't reach 4.8GHz like my 3570K, but it seems to be stable at 4.6GHz while being under 70C load. Not bad.
4x extra threads for 200MHz less clock frequency? I'll take it.