I think now it's FFmpeg that does the GPU offloading (via VDA) in Movist, as its Mac App Store page says:
Thx been a while since I looked, efficiency of both these players under OS X is equally impressive. Same as your observations VLC can exceed 30% of CPU, so unfortunately I dropped it some time back, as for me a Notebook must be portable and have a sustained run time of the "cord" applications that are needlessly power-hungry I will look for more efficient alternatives when ever possible.
Q-6