I'm currently trying a lot of ATs to around level 8 to get a feel for what ones I want to play up further. The mastermind appeals to me however I'm a little concerned that it might not be all that fun to play compared with the action you might find in a Scrapper or Blaster type.
The early levels of a MM seem quite dull. Do they pick up once past, say level 12 (or even 6 with the second henchman)?