After delidding my 4790K and going through several die pastes with what was evidently a bad batch of CL Ultra, I went back again and repasted the die with CL Pro and the temps are looking good, the required vcore is down as well for 4.8-4.9.
This cpu has always run 4.7 at a decently low vcore, but now it extends up to 4.9. For 4.9 I can set vcore 1.32/ Vccin 1.90/ Vring 1.10. Max vcore under load for 4.9 is 1.344v.
So I'm pretty happy with it now that the TIM is straightened out.
Here's a 5.0 validation while running x264: http://valid.x86.fr/bxgc3q
Guess I'll go ahead and try and sell the 4790K/UD5H/4x4GB 2400 RAM and get ready for Kaby Lake.