If you don't know much about the World of Darkness or the old Vampire: the Masquerade and enjoy a more classic style RPG with multiple party control, you'll enjoy this game. It at one time had fantastic online play were you could design your own 'adventures' and a few persistent 'guilds'.
However if your a fan of the old Vampire: The Masquerade you'll pretty quickly notice how much this game strays from the structure of the PnP game. From the inclusion of levels from a dramatic change from the 5 point system to 1-100 system and a great many small differences (such as the huge number of vampires you'll kill in the game, to being able to drink a vampires blood with no hint of diablerism or vampiric laws).
But if you can ignore the differences and what it does wrong, it's still a very enjoyable and classic RPG game. I rate it a three because as a fan of the Old World of Darkness it can grate at times, but for anyone else it's likely a 4.
In the end I'd prefer to see Vampire: Bloodlines which is by far a superior game and was easily the best RPG of year (if buggy, which has been largely fixed and the game expanded upon by community updates.)
In the end this game is totally worth the money, just keep in mind don't expect it to mirror the PnP game in the slightest bit.