I'm having my i5-4670K at 4GHz now - it's stable all right. I tried 4.2 right off the bat the first time and it went batshit, and this was with an AIO NZXT cooler (although I have a Corsair 120mm as a replacement because the guy that gave that nice 280mm NZXT AIO cooler wanted it back just so he could make a sale). lol
Also, we're one CPU off from each other. lol
Now the only question is when Ryzen comes out would it be worth the hype? I want at least a minimum of AMD-Vi on that thing (supposedly equivalent to VT-d for Intel) so when I upgrade or build a new system I don't have to be stuck with a potato Windows installation in its own container.