Interesting results when everything is turned down so low (720p) on the eurogamer site. With a gtx 770 @ 1080 there was only 3fps average fps difference between the 4670k and 4770k.
http://www.hardwarepal.com/best-cpu-gaming-9-processors-8-games-tested/
Granted not the same identical chips, but close. With a 780ti classified, the difference between the older 4770k and 4790k was less than 1fps.
http://www.overclockers.com/intel-i7-4790k-devils-canyon-cpu-review/
Once played at higher resolutions with cards like the 780ti (same as used on eurogamer's tests) the fps difference between the 4690k and 4790k isn't near 30fps, usually far less than 13fps. Some people may still be playing at 720p, but I think chances are if they're gaming with a 4690k/4790k they're probably at 1080 and now many are moving to 1440p.