Gen ed and intro courses were quite large (200+ students). Most professors were accessible. The one thing that I think was really a shock was the curve - I was not used the concept that a grade could be curved downward. My first semester was a shock when I earned As and Bs and ended up with Bs and Cs.
Quality of Life
Housing is expensive relative to what you get out of it. I actually had full coverage of my costs at school with the exception of room and board, and by the end of my four years at BU I came out owing more than 60 thousand dollars. If you are a student coming from a "poor" economic background it is VERY hard to adjust to the culture at BU. There are many students at these schools that throw around the fact that they are quite privileged. A good majority of the people go here as sort of "high school" continued and are more interested in advancing socially, than academically. Overall, if I could go back to deciding my undergraduate school, I would not have chosen the same university.