I dont know why anyone would willingly allow Vampirism to happen to their character. It enforces a bunch of arbitrary limitations on your character for a very minimal benefit. Limitations like "I cant wait/sleep now, ill progress to the next stage", "Oh darn, i cant talk to this guy, my stage progressed to the final one in the wilderness, time to skulk about in some houses for a few minutes", or "I cant fight this opponent, he will exploit my fire weakness and destroy me".
Perhaps im accentuating the negative here. What are the payoffs of having to deal with these limitations? Frost resistances, some powers which may or may not be availiable to you, and a 15% bonus to Sneak and Illusion. My verdict? Woop dee doo!
I would rather my resistances not get touched at all. Before vampirism screws with them, i can handle both elements reasonably well. Afterwards, one becomes a total cakewalk, and the other is an unstoppable [censored] train i cant bypass. No thanks.
Werewolves are fine. A power and immunity to disease for giving up "Well Rested". Fair tradeoff, and not a single aspect of a character that seems to obstruct my everyday play and require me to accommodate for it.

