I actually ran the first part of this recently; my year-and-a-half old AD&D campaign had an influx of new players (with a few older ones unavailable), and I needed a short adventure. So, I downloaded Castle Caldwell and ran them through the first level of the adventure.
Interestingly, the adventure states that it's for a group of 4-8 characters of levels 1-3. I had a group of eight players, most of 1st or 2nd level but a couple of henchmen from the older players at levels 3-4. The first level is *not* designed for a group that large. The largest group of monsters are four goblins!
Of course, most of the rooms are empty of anything interesting. I'm greatly amused by the boxed text, which often states, "The room appears empty", emphasis mine. Some have something hidden, most don't.
We had a couple of thieves in the group (both new players), and they had a lot of fun climbing up to windows (from which they spotted a pair of wolves, which the druid then befriended) and listening at doors. I let them make most of the rolls; it was more than the poor magic-users in the party got to do.
Unusually, it wasn't devoid of role-playing: there are three traders, who I used mostly as comic relief, and a talking statue, which completely confused the party, as it would only talk to Lawful characters. I don't know if anyone actually has an alignment in the group, but as most of the people talking to the statue were thieves, it wouldn't talk to them, although it did answer questions of the wizard!
A couple of weeks later (which was this Saturday), once again I found myself with eight players for AD&D... four new and four old. As a result, we played through the dungeon level of the castle. We finished it in 3 hours (like the previous part), which gives you an idea of how light it is, but quite perfect for this session. Once again, monster numbers were small, but this time I added to them somewhat. The doppleganger was hilarious, as a particularly naive wizard decided to go with him, whilst the rest of the group looked on, hoping to see something entertaining. Alas, one of the new thieves sneaked along behind - rolling the low move silently chance(!) - and was able to save him. Sigh. The doppleganger, at least, put up more of a fight. Particularly once the magic-user of the group (another new player), put half the group to sleep. Yes, four of them. And dopplegangers are immune to sleep spells. Too much fun!
When the dungeon is fairly dull, I can generally rely on my players to liven things up!
The biggest problem with Castle Caldwell and its dungeon is that it just doesn't make much sense. Why is the there a teleporter to a crypt in the dungeon? Why is there a stupid password phrase to get out? I'm a big fan of fun-house dungeons, but they generally have the advantage of being fun!