Tbh Gameworks has grown on me, and at least the less restrictive settings from Nvidia like HBAO+. Playing through Witcher 3, I like Hairworks as well, and the performance impact isn't too bad once you remove the gimping, which AMD has done now automatically (proper tessellation settings etc). Of course, Witcher 3 is more of an exception (in every way).
The problem with Gameworks is the performance, most of the effects already have better alternatives and look better in the process while performing better.
TressFX for me is better than hairworks.