The i7-4790K is hyperthreaded which is actually causing stutter in several Ubisoft games.
I wouldn't consider the i7-4790K unless you convert or edit videos. HT can theoretically benefit up to 30% roughly but in practice it's more like:
a) Gaming: usually 0%, rarely a few percent boost
b) converting video: roughly 15% average time savings for good thread support
*Some people have noted that better threading support in DX12 may justify the i7-4790K however it also means the four PHYSICAL cores of the i5-4690K will be well used at times. Further, the coding is more efficient. My projection is that the i7-4790K is unlikely to give much benefit since we won't need more than the i5-4690K for games in the next several years.
Other:
CPU cooler-> My top recommendations are:
a) Noctua NH-U12S - once fan control software is setup properly the fan idles at just over 300RPM and is SILENT. Barely audible when gaming if no other fan was running (tested myself) and still very quiet at near 100% CPU usage.
b) CM Hyper 212 "EVO": cheaper than Noctua, provides sufficient cooling, but fan is a bit noisier.
See pcpartpicker (about $30 for EVO and $60 for Noctua NH-U12S but haven't checked prices for a while)