Been using mpv the last few days, replacing mplayer2. It doesn't seem to be activating VDPAU correctly despite using the sample config file as a template. The console output clearly indicates VDPAU vo, but I still get 40% CPU usage with HD footage and occasional slowdowns (including the slightly-modified classic MPlayer "your computer is too slow to play this!" message) while playing videos.

While mpv sounds like a good thing in theory, I might just remain content with mplayer2. Now at least a single point has been given.