Yes, perf/w is good, but don't forget Intel has the best technology process 14nm, and we compare to 28nm tsmc(960m). With 16finfet tsmc and 14nm GF the gap will be closer.I think what OSX7 is getting at is if you put these numbers into performance/watt, the 6770 is pretty darn impressive, and that certainly is in sync with Apple's apparent direction.
Hopefully we'll still see an Apple product with a Polaris/Pascal gpu at some point, though June might be a bit optimistic for that.