One more thing. The reviewed Fury X is a match to stock 980Ti (1000Mhz base/1075Mhz boost). Aftermarket 980Ti from ASUS, MSI and Gigabyte will have better power limit, cooler and quieter fans and much higher clock. MSI's 980Ti Gaming 6G have 200Mhz overclock at base and boost speed (1178Mhz base/1279Mhz boost). Overclocking GTX further to 1500Mhz at default voltage is also common and at those speed even a Fury X overclocked from 1000Mhz to 1125Mhz (Guru3D's overclock) will not stand a chance.
Why would you think the Fury would have less OC ability? I would think once Aftermarket GPUs are out it would be much more easily overclocked and get more benefit from it, with that fancy panse memory.
3 reasons:
1, GCN 1.2 don't overclock as well as Maxwell and Fury is a tweaked GCN 1.2.
2, Guru3D only managed a 12.5% overclock to 1125Mhz. They think they can get it up to 25% at 1250Mhz if the overclock app is more mature and they can give it more voltage.
3, If the reference card is water-cooled at $650, how much can board partner sell their air-cooled Fury X? $550? $600? You cannot replace a $100 AIO water-cooler with a $40 heatsink and sell it at the same price.
Then looking at 980Ti which overclock 30-40% at stock voltage on air and 50% on water, you'd see how overclocked Fury X is not a match for overclocked 980Ti.