I have to share a little story about how much fun it is to send one's players against a cabal of seven vampires. SUre, I had to make a few updates form 3.0 to 3.5 and sure I pretty much ditched the entire adventure background to make it fit into my campaign, but it has worked out fabulously.
My players are all pretty much very experienced players and rarely make the mistakes of the less experienced. however, I have gotten tehm to do something that I never thought would happen -- they have split the party into two groups, and hilarity (for me) is about to ensue.
The PCs, consisting of a dragonborn cleric of Bahamut, a female human fighter/dervish, and female fighter bow specialist, an elven rogue slowly being lured to the worship of Vecna, and a Neandethal druid/warshaper have been sent to find a Lord Valdemar to gain legitimacy for the castle they have claimed. The magistrate that sent them on this quest knows that Valdemar, in my campaign, has been missing for over a decadea dn thinks it is a wild goose chase. Meanwhile, the PCs were joined by the bow specialist's sister, who is now a paladin/vampire hunter who has helped them out immensely in terms of knowledge of what they are up against and good methods to destroy vampires.
So on the first day, the PCs have pretty much stormed the castle and investigated the first two floors plus the tower, and have slain three of the seven and are in hot pursuit of a gaseous form of Valdemar, but have nearly exhausted all spells and are at about 2/3 of their hit points. The cleric and the NPC have "herded" Raven's gaseous form to an area where they could let in sunlight andhave just destroyed her, and are about two minutes behind the others, who are pursuing Valdemar's form into the basement.
Even more fun, they managed to set fire to some spare coffins they found, as well as allow Raven to summon some three-score of ravens, adn the ensuing smoke and commotion have awakened the two remaining vampires, Valk and Haroun, in the above-ground portion of the manor. Those two will take several minutes to prepare and then pursue, but will be several minutes behind the PCs.
SO it looks like this: If the PCs are dilignet, they have a cahnce to pursue and destroy Valdemar. If they linger too long, they will be assaulted by the ramainder of the Heptad, and likely perish. If they leave now (or soon), they will hole up in an area where they will likely be safe, but the nearby town will be victimized, and the vampires will preapre. In any event, this has been an exceptionally fun adventure so far, and it's only going to get better as I get to start playing the vampires being aware of interlopers and plotting revenge. And it does tie into my campaign, since one of these vampires is the "cousin" of a staked vampire in the basement of the PCs castle...
This particular adventure holds the honor of having been run twice for my players--once, using 2nd edition rules in 2002 and then again, using 3.5 rules, in 2006. Only one player had a "vague" recollection about having gone through it before, although another one later claimed that the gorgon in the courtyard seemed awfully familiar to him. Great adventure--I, as a DM, had a blast with it.
Kind of weird that I ran this adventure twice, but never using the rules that it was designed with--3.0 !