I was skimming through the High Defense, High Crowd Control characters yesterday (Braccus, Ares, and the girl with the shield come to mind). I played Arena since Conquest didn't unlock until level 5, and I felt like I was able to contribute more as an HDef/HCC or HDef/High Sustainability class since I was dying less. I did like Apollos mobility, though.
I do see the appeal of the game. It's far more engaging early on than any other MOBA I've tried. If "easy to learn but hard to master" is the golden formula, then I'd say Hi-Rez has the easy part down pat. The tutorials, character synopses, and auto-skillups + auto-items take away all the early game anxiety. I really had an opportunity to focus on the class I was playing, the environments, and study the items it chose for me. Good stuff.
They do a really good job on bringing new people up to speed but once you get a little confident try lvling without the autolvl and auto buy items. You will begin to destroy others when you can master it.