Labels are what make Gmail... Gmail, that and its implementation of conversations. Given a choice, I'll take labels over "standard" IMAP any day--having something that works better is always preferred. Properly configured (meaning the way Google suggests), an email client works fine with Gmail's IMAP. Frankly though, the fact that Gmail has any IMAP support is something of a wonder--one of the few things I commend Google for.
"Face piles of trials with smiles; it riles them to believe that you perceive the web they weave."