I have to disagree with that. I really am not seeing the problem. At the college I teach at now, we went through a huge change several years ago when we dropped from 60/90 to 50/75. It completely changed the schedule around (even more so since we have 15 minutes between classes) and I don’t remember a single problem. And to elaborate, due to the 15 minutes between classes, classes on MWF are now 8:00 -8:50, 9:05 -9:55, 10:10 -11:00, 11:15, etc. You tell me when to be in class, I’ll be there. And it really is not any harder for a professor to end at, say, 10:50 versus 11:00. Students usually subtlely and not so subtllely give you hints if you’re going long anyway.