That's about my experience too, having done only two classes so far. One of the largest downsides (in my experience) is never meeting/hearing from the instructors of the courses- the TAs are almost solely responsible for running the classes. I went to a large state school for undergrad, so lack of instructor facetime has not really been an issue for me. I've also found many of the udacity lectures to be so-so, but the GA tech projects really help to drill information into your brain and can be quite time-consuming.

Yeah, people who think online ==== easy will not have a good time. I love OMSCS, I'm about to start HCI this summer. It's great because I have a mortgage and a career - the amount of debt to go full time would be staggering, and the cost of attending private classes would ruin my long term financial goals. Also, I just really like it.

I'm on my 9th class, one more to go. I found that Machine Learning had decent involvement from Isbell (he'd chat with us on Slack) and that Operating Systems and HPC and excellent professor participation -- they would hold weekly office hours (video conferenced) and were active on the forums.

There were 1 or 2 of my earlier classes that did feel phoned in, though (but did have strong TA involvement at least).