Pros
People are very nice and are helpful and it is a good place to have a fun work life. This is manager dependent but the work is interesting and people are more than happy to show you what they are working on or answer questions. As a co-op it is a great place to be taken seriously and contribute meaningfully to a project. The length of the program is definitely its greatest strength.
Cons
Management is is probably the weakest part of my experience there. I did not personally experience some of their ineptitudes directly as my managers were competent and trustworthy, but specifically parts of upper lab management as well as the infrastructure around it, at least while I was there, was highly unorganized and slowed down the easiest of lab requests. There are also too many one-person labs which also contributes to this problem. Also co-ops were pretty disconnected from one another, but this can vary from year to year.