Tricky, yes! I took chem 130 and 125/126 in fall of 1997. The semester was a disaster...! Most of the class was confused, most of the time. Parents complained so much that C's were curved up to A's. The tenured professor, Dr. Henry C. Griffin (whose name is indelibly etched in my brain) lost his job over the mess.
I retook General Chemistry in 2006 at another school and it didn't seem as intense as it had seemed all those years ago at Michigan -- it was broken up into two semesters. I performed much better.
This discussion seems to support that Michigan does things differently. So am I crazy in thinking that Michigan probably combined all the material of other places' Gen Chem I and II into one semester? I tried to block it out, but it makes sense that I struggled with it so much if that was the case.