This game reminds me of Mass Effect 1 (haven't played ME2 yet). If you don't do the side quests this game will be very very short. I did almost every side quest (minus 1 in ozimmar) and it took me 50 hours(give or take) to finish this.
I kinda feel like this game wanna incorperate WoW elements in it, ie tank hold agro, dpsers dps enemy, healer heal. You'll probably wanna be min maxing so that you can maximize your character maximum potential. So much for role play...Then again, it's probably because I came straight from playing WoW.
Oh, the most annoying part of this game is the area loading, I believe I spend a lot of time waiting for the area to load. The longer you play the game the longer the area will load.