I don't come from a min/max mindset when I choose builds. A lot of it is "how fun is this when I level?" I have an incarnate Thugs/Kin who has a ton of damage and utility. His concept was fun to create. But making my Bots/EA, I have a great concept and really enjoy playing him. I'm not a giant fan of the 50 game for MMs outside of all-MM TF runs, etc which are hilariously enjoyable IMO. But EA has a lot to offer and if I end up on a team that has little in the way of buffs, I can fill the gap by keeping everyone and my henchmen healed, absorbed and +rech/+end in addition to running my bots. I just like the flexibility of play style of an EA MM on the way up.
I enjoyed the secondary so much that I made an EA defender to compare and both are enjoyable and fairly flexible to the team.
Now, soloing, taking on AVs and all kinds of high level insanity, I can't speak to. But it's been very fun to play in groups and enjoy the concept.
Depends how you play the game, I suppose.