Finally got round to playing this with my group, and it was a blast! They got very nervous at being separated, and asked several times if the vanished party members were still alive... having spooky background music just made it the more creepy. I had a party of six level 6 characters, whereas the adventure is optimised for four level 7 characters - it made the individual encounters in the various rooms a bit tougher, with a couple of very close shaves, but the final encounter was quite easy with so many PCs, so it evened out in the end. Thanks for a great adventure!
[4 of 5 Stars!]