Which is better DIVX or XviD when playing .avi file?

[sleeplessrevolution]

This is not a question if which is better among the two (2) codec pls. refer below. thanks

I've been wondering since any of them can play .avi that are assosciated with them, wouldn't it be better if you just choose either one of them?

But then, basing from your experience if the video is encoded with XviD did it look better when playing with XviD as the chosen codec and same with DIVX vice versa?.. Because in my experience between that two most popular codecs when playing .avi files i don't see any difference in quality at all? Or it's just me?...