I've been taking an extended break from Skyrim and haven't played since before the release of Dawnguard. I downloaded Dawnguard and looked over Hearthfire but the latter didn't interest me much, at least for the moment. Anyways, my favorite builds were mage builds but they tended to suffer in the late game, relying on dual-cast stagger locking some of the toughest nasties in vanilla Skyrim. Are they any better with the addition of Dawnguard?
As for additional information on my RPing tendencies, I don't like doing -100% Destruction Spell Cost custom enchanted, and my mages tend to be either Altmer, Breton, or Argonian.