Benchmarks I’ve seen aren’t quite as conclusive as you claim. Increase the resolution to 2560x1440 or 4k and the Mantle advantage twindles. Yet those resolutions are exactly what we need in VR. So I cannot really agree with your assessment that Mantle + VR would be a great fit. I’m not saying it would be bad, but is it really worth it to dedicate considerable development time to support it in UE4 at this point before even the main gaming video card manufacturer jumps on the bandwagon? I don’t think so.
Meh, edited out unneeded stuff.