Used to play it a lot when the orange box came out. Once they started introducing items and stuff, I had stopped playing. Item introduction just made me not want to play that much more. (Non-level playing field)
Like most games at that stage, some characters were broken (Just takes 2-3 engineers, no FF, and no one could ever penetrate your defense). And like every freaking source game, there were tons of registry and lag problems. (As the sniper guy, that was really annoying) I still play CS : GO even though it has those issues. >_< (Infuriating at times)