Anyone who says any class is OP is wrong. Blizzard has a pretty large consumer base, and I don't think they'd actually mess up bad enough to make a noticably OP class. They must be doing something right if that many people will play this game. People who can't win in a duel and whine about OP classes are just sore and looking for a way to keep their pride, because most people who hear "I fully accept the fact that you beat me fairly" will reply "Yeah, that's right, noob!" rather than "I am also aware of this, and you put up a very good fight. Thank you for duelling me, I hope to meet you again." Point is, MMO's are the most cutthrought world of nerdery there is, and people are jerks a lot. When lots of people are jerks, your immediate asumption is "this guy will be a jerk". No-one wants to think that, but subconciously, you all likely have at some point. Imma dun wit mah psychological talkin now. Mah brane neds a rest.

P.S.: Those who didn't just lose a duel likely have in the past, and are still licking an ego-wound.