Flexible class hours, Affordable
Assessment is questionable as anybody can retake tests to get a better score and the peer-reviewed tests are a bad idea when your peers are not very knowledgeable, especially on such a difficult topic.
You work on your own time. There was a lot to learn. More graphics would help to illustrate difficult topic. There are tests and quizzes but there's no limit to how many times a person can take the quiz and if you just remember what the last multiple choice questions were you can get a 100% all the time. Peer-review assignments are a joke because your peers might not be very knowledgeable about the topic so they would be the wrong choice to evaluate you.