I really enjoyed this quest, I thought it created a good sense of place and the dialogues were all fun to read while trying to puzzle things out. I only saved three of the guests on my first attempt, and enjoyed my second run through more than I thought I would given that it's considerably simpler once you know what you're doing.
As it seems like we all have stories of boss fight misery, I'll share mine. I wasn't using a silver weapon, because I was rather attached (and indeed, weapon bonded) to my fallen moonblade. So, when I was hitting the boss and seeing insane levels of DR, I figured that was just my rightful punishment for being too rigid / lazy to come appropriately attired. You see, I'd already smashed the pillars and thought I had the Vampire in the light... turns out I was standing him in the wrong place. His real silver DR, which I figured out when I moved him an inch as a result of him going into batswarm mode, was totally reasonable. D'oh! Next time through I kept "z" open on him so I could see his "standing in the sunlight" debuff and make sure I had him in the right place. That was silky smooth.