I disagree with MasterMinds being difficult. Solo-wise anyway they are beasts, especially when you start getting more henchmen. Bots are quite useful, I ran bots/traps back in the day and it was awesome soloing through entire waves of enemies without too much hassle even on the higher difficulties.
I view MM's as sort of a tactical class, you're not supposed to hang back or rush forward but rather mix and match as the situation demands it.
Team-wise they're quite useful too, I used to duo with a good friend of mine on red-side and it was excellent fun steam-rolling everything that appeared in front of us. It was intense since we both liked a challenge and ended up putting the difficulty so far up we had purples nearly every single mission which, led to a lot of patience in taking down enemies.
In my view they're quite versatile. If you start one it's good to take it slow (as always anyway) and enjoy the game while learning gradually how to utilise the MM in both solo/team play. Once you're confident with it, it's quite easy to crank up the difficulty just to see how well you can cope with the excesses of enemies and so forth. If you ever get a friend to duo with, it's even better. One of the best things for me duoing back then was he, like me, took the time to read missions and text and generally progress together at a relaxed pace.
As a MM, patience is a virtue for world-conquest