I've never taken a course that was fully online, but I always wished I could.  I'm OK with keeping up and working at my own pace.  Unfortunately, most of my courses were "seminar" meaning participated was required (often graded) and there'd be like a max of 25 people in the class, which was more of a discussion than lecture.  You were expected to read and know all the material beforehand, and class was used to take it further.  Bleh.