Just rewatched this episode, and even after several years, it's still just 'meh' to me. The professor/student dynamic creeps me out, and the whole story (yes, including the Donna angle) just didn't interest me at all. And I found it rather unbelievable that in the scene where Al was trying to convey info to Sam in front of observers who were inside the imaging chamber, it took them that long to realize that that was what he was doing. I vote "Average" for this episode.