Ah I didn't realize the Piazza post isn't publicly viewable, thanks for telling me. I recreated it as a screenshot now https://imgur.com/gallery/GtuF78M

This is a course 6 issue mainly. Course 8 and 18 I've had generally good experiences with (but I'm a course 6 major).

As for OCW, I think it "looks" complete, but it's actually not very useful because so much material is missing e.g. no pset, no solutions, only lectures but no notes, only lecture notes but no recitations, etc. etc. which is why I know Aayush and Ashay are working on https://mitsoul.org/

Anyway, thanks for your comment!