Years of twitch gaming has made me extremely OTT on all things smooth and input lag related so I trust my judgement to notice if anything was different upon trying Mantle.
But, no, there just really isn't anything there for me with single GPU with a high end CPU.
Is it really the end of the world though? It isn't really what Mantle is supposed to do. It's about bumping performance of low-end CPUs and alleviating the bottleneck for situations where people have a ton of GPU grunt (e.g. CF)
I'll be playing more BF4 today so we'll see again if owte is different. I'll be on the DT maps and as that's all I've really been playing in the last couple of weeks will give me a better point of reference to the 780.
Urgh vsync. That's like swearing at me
I play full ultra and then: 2x MSAA, no motion blur, vsync off. 1920x1080 - 120 Hz
I don't drop to 50s with those settings. It's 70-80 at the very worst. Normally the minimums are around 90. I don't yet know what they're like on Mantle as not monitored properly.