Remember,the GTX480 and GTX580 were the Titan and 80TI cards of their days.
Nvidia and AMD have progressively bumped up the top end cards from £400 to £500 to £700 in the last few years,with the Fury,Titan and 80TI brand names.
Both the GTX470 and GTX670 were around 20% faster than the GTX285 and GTX580.
According to TPU the GTX680 was only 10% faster than a GTX670.
The GTX970 traded blows with a GTX780TI/Titan Black for less money(in both dollars and pounds),dropped power consumption and was on the same node.
The GTX1070 cannot even do that. Remember,this is a better the one node shrink. The TSMC 16NM and GF/Samsung 14NM process nodes are third generation 20NM based processes.
So after 4 years on 28NM,people are amazed that the GTX1070 can just about match the Titan X??
This pretty much means the £250 GTX1060 and Polaris 10 won't be significantly faster than a GTX980 or R9 390X otherwise they will be way too close to the GTX1070.
It pretty much means probably another 20% increase.
It also means,we need to wait until BOTH the GTX1080TI and Vega10 are released,to put some downwards pressure on the slower cards.
But we can OFC agree to disagree and leave it at that!!