I enjoyed learning how to code in a new language, and learning how to build an app. The learning was very open-ended, and I could practice in whatever way I pleased.
What I wish was different
I wish that there would have been some non-remote aspect to the co-op, as I never got to actually meet any of the people I was working with face to face.
Advice
I would suggest that anyone who wants to strengthen their computer science knowledge in between semesters should do a co-op like the one I did.