First off, no, this does not belong in the dawnguard sub forum.

I still haven't played through Dawnguard, despite purchasing it on day one. I keep re-rolling characters - that is when I have time to play the game. I have a four day weekend, and I want to sit down and hopefully get into Dawnguard a bit, but I want to have a high-ish level character for it. What type of character do you guys think suits the roll of vamp hunter best?

I think any type of character could fly. That said, their signature weapon is the crossbow, so I'd say an Archer of some sort if the best. Since the crossbow is a weapon of initiative, ending fights before they begin, I'd also say a stealth character would be useful. But, really, they also have a ton of anti-undead spells that would fit a paladin. Really, any build could pass as a Vampire Hunter.

How are the new "anti-undead" spells?

Pretty darn effective.