For years, I've used VLC and haven't thought about it.
It just works. I've never used any "settings" in it other than play and pause.
However, I'm not sure if it uses "all the features of my ATI 6850."
Presuming that my ATI 6850 has any features that make video playback "better."
Should I blissfully and ignorantly keep using VLC ? I don't really have anything bad to say about it; I just don't know if I could get something better; and "get something better" would include a large helping of me not having to dick with it to get it to perform.