Stick with i7 7700K. It's not worth replacing it imo. Especially not for gaming. Just overclock the hell out of it and you're set. I'm on 5820K at 4.5GHz and I don't see a single need to upgrade it. Reality is, if I didn't have global problems with my old X58 platform, I'd still be on my overclocked Core i7 920 I think. Or it's very likely that I'd be switching to Ryzen 7 when it came out. But because of problems, I was pressured to upgrade. 7700K is pretty damn good CPU since it clocks really high with good cooling. And for games, clock is still the king. It's only recently that just few games show some gains with more cores. But 7700K still has 8 threads, that's plenty enough.