Good and Bad: Good if the professor wants to stay around and be a great teacher. Bad since it usually means that the professor can slack off and do absolutly nothing teaching-wise since there is little that can be done. Latter is ever more true when talking about people that bring mad bank to the university (eg famous authors).
I have had experiences with both; although some teachers want you to learn stuff well, and they believe in the trial by fire method....very stressful at the time!