QT is no good. just use VLC
Plex is the best, VLC is too processor intensive for 1080p on OS X, and can cause lagging, skipped frames, and poor resolutions on anything other than the best processors.
I've never heard of Plex, but I can see it is pretty popular with Mac owners. The problem is that I keep getting this "Mounting Failed" whenever I try to download it. Not to mention it is really slow downloading speeds, but I am at college. Anyone know what to do?