So, assuming I didn't have my 290 CF setup, your solution to this Mantle issue is to buy new graphics cards?
If a game played fine on an Nvidia card and barely worked on an AMD card and the developer said they wouldn't be fixing it, there are a lot of people that wouldn't be happy with the solution "Buy 780Ti's to make the game run ok". But "Buy AMD 290s" is a perfectly fine solution in this instance?
Also, where is this "known issues" coming from? Link?
Thracks has said that the 7000 series cards have parity with the 290 cards as far as Mantle goes, so you're saying that the Frostbite engine treats GCN 1 different to GCN 1.1? Why would it do that? Does Mantle mean that they need a separate rendering path for each architecture or each graphics card model (That's gonna be a lot of work in the future as more cards support it)? Or did they purposely sabotage performance on 7000 series cards to help AMD GPU sales?