I just did the first quest for the expansion that makes you actually go somewhere (not gonna mention where) on my dawnguard character and as soon as I left the cave, decided to go do some radiant companion quests as well as the quests that give you the agent of Mara perk.
On my vamp, I received my new ability (Not going to say what) and went out and did radiant thieves guild quests as well as tested out the ability.
How are you guys going along with the questing? Are you trying to draw your experience out as much as possible as I am?