Well, sure it doesn't. It just prevents you aging, while giving you a vast suite of easily-exploited, well-known weaknesses - some of which appear to be psychological blindspots/compulsions, and the rest of which instantly and permanently destroy you, and are easily duplicated (but not easily negated, for the most part) via magic. Oh, and your STR and DEX scores go up a bit, I guess.

Disclaimer: This assumes MOR!Potterverse!Vampires don't run on the Buffy you-get-replaced-by-a-demon principle or the Anne Rice tortured-romantic-deathgod principle, AKA Twilight Syndrome - but still retain most of their standard pop-culture properties (as do most Potterverse creatures that aren't original creations.)