The issue I have with this is since AMD's GPU's as of right now don't have dedicated hardware for these calculations, so in the end you would have less cores rasterizing since they'd be running calculations.
On CPU's if the user has an 8 core or more CPU they could potentially offload the calculations to cores not being used by the game, if it's possible, but then those that have 6 or less would be SOL.
That's my main concern with all of this, Nvidia has dedicated hardware to run the calculations whereas this has to run on your standard hardware that most likely won't be able to perform the calculations as well, time will prove my worries either right or wrong.