Judging from Vampirism's artcle on UESP, they seem to be, more or less, the same as they were in Oblivion. In the sense that there's almost no benefit for being one.
My idea was, I wanted to try and be one as early as possible with infection and try to play through several levels as one, consistently. But it just sounds... unfun.
Specifically, the fact they health and stamina don't regenerate, even at stage 1, when you're outside. That's a fairly debilitating issue.
As a final note; Vampires were good in Morrowind because at least there were several quests dedicated to just them. They really need to bring that back if Vampirism is to have a reason to be in the game.

