I'm currently a Biology and Math major. The courses offered really help in my understanding and I feel it will really help me find a coop. The workload is a lot if you want to do well. The professors are usually really good -- good communication, telling you what they want out of you, etc.
Most of the courses for science majors have a ton of people. It is only when you get more specialized that you have smaller classes. Even courses like genetics (200 students), biochemistry, and ecology have large amounts of people