Has anyone tried the courses in the ML or core CS areas? What'd you think?

The ML course is interesting. Some of the lectures are a bit chatty and the official course text book was written in 1997, but it’s a great survey of many different ML models, including Neural Networks. It’s a good segue into Deep Learning where you explore more advanced NN architectures, beyond Feed-Forward NNs.

For core CS, I found Graduate Intro to Operating Systems very rewarding.