The biggest problem with Spiritland is that letting most DJs touch this kind of equipment is like putting a small child at the controls of an airliner. On Saturday night, the featured DJs ran the tweeters extremely "hot"; the sound was painful. They succeeded only in ensuring that the room was mostly empty (there were perhaps a dozen people in the main room at 11:30 p.m.).
So, go when they don't have a featured DJ (which is during the day, every day) or when there's some indication that the DJ will know what he's doing (e.g., the DJ will be doing a Rudy Van Gelder retrospective). I do recommend the place, and the food and drink are excellent. There's no dancing and no excessive drinking at Spiritland--it's civilized, relaxed and focused on the music.
I will go again.