I guess if you need to hit 144FPS for your monitor then Mantle is significant. Otherwise, I'm just not seeing it in the high end.
You're pretty much fine if you have an 3xxxK or 4xxxK past 4GHz in this game, even without Mantle.
Well, there's the Multi-GPU factor, but that's not really working properly right now so I'll refrain from commenting.
144fps? Where did that number come from?
Besides from the made up number, there is just the problem with this argument that those that actually game dont agree. H for instance.