I promised myself to not get into this thread, but I remember someone asked a rhetorical question: Why doesn't AMD post such 'Guide'.
Well, they actually did in a form of Mantle/Vulkan/DX12 manual.
And even if that is not enough, why would anyone think, that it is so important to leak such guide for devs to general public???
The reason why nvidia actually published such a guide only now is just a damage control. Since any normal company would have had such guides published before dx12 was released, not several months after official release. And any normal company would have sent these guides to actual devs, and would not publish/leak whatever was done with these guides.
And I seriously LOLed at someones twisted understanding of market share

*slow clap*