I'm basically on the same line.
I find the game very well designed to handle Action Scenes (well, Fight Scenes, mostly) but not very well equipped for anything else.
Even in the metagame structure itself: Action Scene/Transition Scene/Action Scene...
Which is obvioulsy a design choice, no problem with that.
No much room for Social Interactions, for example. Of course, we can handle that using some Specialities or a few Powers but that's still limited (no real way to shine, as Mouse said)
That's why I guess I'll use MHR for one-shots, more or less lengthy, because I know that after a very short time.
Anyway, we're in the middle of a Smallville|Gotham campaign, with tons of non-combat scenes but I must say that action-oriented scenes are somehow too short and lack color...
Can't have it all !