None of the above really matter as long as any of them include the idea of "learning from your peers". If I pay a university to teach me something, they'd damned well better stick a relative expert on the subject matter in front of me for 40 hours over the next three months, whether in person, in realtime, or just "on demand".
Far, far too many online courses have roughly the same format as a Slashdot FP - Post the day's reading material, then require students to "discuss" it. Except, just like with Slashdot (browsing at 2+), the first few comments (almost always by the same few people) pretty much say it all, and everyone else tags along with "me too" - Albeit phrased much more verbosely to get credit for "participating".
Sorry, but I didn't pay to chat with people who know as little, or less, about the subject than I do. I don't have any interest in "learning" by helping my classmates catch up. I honestly do not give the least fuck about my "peers", and if I could afford to, I would have much preferred to only take classes with one-on-one instruction from a subject matter expert.