Dude I did it on a brand new 8700k and it worked flawlessly. You hit 5.0 really easy and keep your temps around 60 with an AIO with a full load. Its super easy. Just don't put to much. It shouldn't be pooling up. Apply it to both CPU and bottom of IHS. Scrape off all the black sealant. Get silicon marker at any auto parts store and put very little around the edges. Like the thinnest layer you can all along the edges. Bam. Your done.
The gains to be had are pretty clear, but unless youre OC'ing the piss out of your system then its probably not worth it. But as others have said, if youre going to attempt it, buy the correct toots because its a pretty delicate procedure