We went to this place on a Saturday night after trying to get a table at a different Thai place on Willy (long wait, so we left). At Bahn Thai we were immediately seated and the place did not seem terribly busy; however, after ordering, we waited 40 minutes for the appetizer, and then another hour for the main course. A beer that we had ordered when the appetizer arrived was served with the main course. I do not know if they were short on staff that night but the waiting time was unacceptable especially since we had small children with us.
That said, for Madison standards, the food was good but the wait, I dunno.