The allips were 10th level monks, in addition to being advanced in hit dice. They were effectively CR 21, iirc, but they didn't get all the feats they should have (in particular, some of the Eberron monk feats they should have had, due to my failure to forward the correct versions to my home address), which is why they were considerably less effective than they might have been.
When I have a chance, I'll post their stats to the thread that must not be named. Mind you, no one batted an eye when they encountered a vampire monk in the lobby.