Here's what I learned from DMing this campaign killer:
- It's repetitive as hell, to the point of being boring;
- Gulthias has so many tactical advantages that you must go out of your way to play him too dumb/vain/disdainful to salughter the whole party;
- The maps can't accomodate a 3.5 game, because girallons now have a 10' space;
- Your fighter/rogues might as well not have any rogue levels, 'cause sneak attack is useless in this adventure;
- Unless you use the Complete Divine variant for Turn Undead (turn = 1d6 damage to all undead in a 30' radius, save for half), your cleric shouldn't do any turning at all, 'cause turned undead will only alert the others;
- Deadly adventures are good, but too deadly and they get frustrating.
- Let your players roll new characters in advance.