As far as I'm concerned a game's system is irrelevent to how the game is actually played. A d20 Cthulhu campaign and a d20 Oriental Adventures campaign for example would be radically different animals (unless the Oriental Adventures game had a really perverse DM!).
Personally, I like some things about d20 and not others. The big advantage of it is that it is a standard - so for most players, learning a new game means less time learning a new system, and more time experiencing it.
Personally, I like some things about d20 and not others. The big advantage of it is that it is a standard - so for most players, learning a new game means less time learning a new system, and more time experiencing it.