As lolfail9001 stated everything still points to that performance even compute when you look at what does what in optimized software.
Tflops increased by 30-40%, FuryX is at 1070 performance, that means if perfect scaling, Vega ends ups at gtx 1080 or just above gtx 1080..... and from the past we know AMD's scaling is never linear when it comes to adding cores. Factoring in front end enhancements of Polaris, it should hit that estimate.
No he never talked about Primitive Shaders so don't know where you are getting that from, unless you heard or read something that I didn't. Everything so far I have heard about Primitive Shaders, they must be developer handled, and they will help Vega but to what degree its up in the air.
I quoted you on it in another thread. I don't think you read it. Raja responded to a question from a student. He said new geometry pipeline, primitive shader and culling shouldn't require anything from developer standpoint (this is not exact quote but his answer was pretty simple and straight forward.