XenoPrime

Absolutely not. My current 'default' toon (cant say Main, as I'm an unrepentant altaholic!) is Mercs/Dark, and she's a complete blast to play. CoT's a pain to fight and avoid Malta entirely, but everyone else is grist for the XP mill.

As has been stated and repeated in this thread, at the end of the day you're still a Mastermind, and still one of the most potent AT's the the game. It's all about the fun and the concept; if the latter works then the former will follow.