The guy who has 4 fury X knows better then you and has enough experience to claim things.
Actually if you run a QuadFire rig, you have enough GPU power to crank max AND max MSAA or SSAA at 4K, at which point, 4GB vram is NOT enough.
This should be quite obvious and well known.
4GB however, is plenty for single GPU and even 2 GPUs, because they lack the performance to max settings AND use MSAA/SSAA. They have to make do with FXAA/SMAA.
So yes, at the rare 4 GPU setup, Fury X is pretty crap.
However, in CF v SLI, it dominates and even factory OC 980TI can't match them. You need to max OC the 980TI SLI to match stock CF Fury X, and that's in DX11.
The lead will only grow in the DX12 era.
This is great for gamers who hold onto their GPUs for a few years, but doesn't matter to folks who upgrade often.
The one thing I don't get, is you desperado, you like to rub it in and make fun of people who buy Fury X. You often compare it to custom OC 980TI that are more expensive. Yet you ignore the advantage of Fury X, it may suit people more who like their rigs to be quiet and cool running, all that heat out the case. Water cooling has its advantages. Despite this, they are quite close on performance in many DX11 titles.
Now the trend in DX12 so far is Fury X gets a nice boost. 2016 so far has a good line up of AAA DX12 titles, you may find, by the middle of 2016, Fury X pulls ahead more. So, why the nasty attitude? You enjoy your 980Ti OC, let others enjoy their Fury X.