You know, I got to thinking about the 'VTM_D20' vampire character idea and realized that it might not be the right way to go if your players had plans of returning to non-vampire form. The problem is that if they play as vampires for a while and gained levels as vampires, what would happen to the character levels when they were converted back to human/elf/etc.?
I know that if I was a player and was faced with giving up one or more character levels, I'd be reluctant to change back.
Of course, if they were going to keep their vampire status, then there wouldn't be a problem of loosing levels.
That's the problem with any template that gives the players more powers than drawbacks. The players will become reluctant to give up the power.
I remember once having to play as a character with the werewolf curse. The GM did well though in that as a new lycan, I had no control. I, the player, lived in constant fear that I would injure, kill, or turn another. I especially worried about the innocent people/children. It got so bad at one point that I was ready to have my character commit suicide, by fire or acid, to save the children in the area. Luckily for me, the GM had an entire plot around my lycanthropy, including a means by which I was able to rid myself of the curse.
But, I digress. My point is, if you and/or the players plan to keep the vampire curse, then make it a bit more beneficial that drawback.
If you and/or the players don't want to keep the curse, then give them a little more drawbacks than benefits and a tough, but doable, way to rid themselves of the curse. Also, give them a reward for giving up the curse and it's powers, even if it's only the eternal admiration of the locals who know what they achieved.
