ALso, Fury X seems to be superior at SLI:

But what about that direct AMD and NVIDIA comparisons? Despite what we might have expected going in, the AMD Radeon R9 Fury X actually scaled in CrossFire better than the NVIDIA GeForce GTX 980 Ti. This comes not only in terms of average frame rate increases, but also in lower frame time variances that result in a smoother gaming experience. In several cases the extra scalability demonstrated by the Fury X allowed its dual-GPU performance to surpass a pair of GTX 980 Ti cards even though in a single GPU configuration the GeForce card was the winner. GRID 2 at 4K is one example of this result as is Bioshock Infinite at 4K. And even in a game like Crysis 3 at 4K where we saw NVIDIA's card scale by a fantastic 84%, AMD's Fury X card scaled by 95%!

While not a great jump in performance, the Fury is at least priced (mostly) correct. AMD really needed to drop $50 off each of the Fury cards. $500 with 10-15% greater performance and same RAM as the 980, is very compelling.