I had managed to get my hands on a Sapphire RX Vega 64 when a few went on sale on the egg before selling out again. I've been waiting patently for something to drive my fairly new ASUS MG278G through its proper paces. RX 480 and Fury don't cut it.
Vega 64 puts my aging 660TI to shame in every way. The card itself a 1/2" longer then my previous 660TI but still fits itself my Fractial R4 Define chassis with some clearance to spare. It easily yields three times the throughput of my previous 660Ti but at a cost though. The card itself gets toasty fast running at 80C+ when fully loaded and you could probably slowly cook eggs on the backplate.
I haven't touch on the fan controls/undervolting yet so I can dial things down a bit.
As for as gaming performance, my current [email protected] clearly holds the Vega back but it still manages to deliver ~120-150FPS on newer franchises at my monitor's native resolution (2560x1440) with all of the works. Freesync eliminates screen tearing and makes motion blur look more "natural".
I'm aware that 1080Ti is faster with lower power consumption but you need to get a Gsync monitor and Nvidia has no incentive to support Freesync in light of Vega's lackluster launch. It feels like Vega 64 is Hawaii 2.0. There's potential in the hardware, but the real issue is coding the software to properly harness it. Nvidia has a massive jump start here. I wouldn't be too shock that Vega 64 manages to distances itself from the 1080 in next year or so, but it will never catch up to 1080Ti in terms of gaming performance.