No one has responded to this and it's been a couple of weeks.... I do not have much experience with online classes, but I can tell you about it... I am an audio learner, so if I hear a lecture and can interact with the people in my class, then I do really well. I did not read one textbook throughout my undergrad (4 year) degree, and still graduated in the top 5% of the class. I tried to take one psychology class online and we were required to all read everyone's comments and respond to 5 or more. There was no way I could keep up when there were about 60 of us in the class - and do the textbook reading on top of all that. I spent more time on that one class than I did on all the other classes combined. I dropped the class after 3 weeks.
But... I took a couple of my teaching courses online and since it was really well structured and the reading was not so intense, I did well at those. The classes were also much smaller - 25 or so, and we were put into discussion groups so we didn't have to read everyone's comments, just those in our group.
I think online courses have come a long way since then, with a combination of video, audio, and live chat rooms, so I'm sure that makes a difference.
My husband has done most of his master's program online and since he is a speed-reader and well disciplined, he does well with those. My preference is in class, interactive, audio/visual, and structured.