Since you're participating in a discussion in a MOOC, you can provide data that others (including me) don't know:
How large is the Harvard CS50 MOOC? About how many people are participating in the Discourse discussion?
Approximately how many messages are posted in a day?
How do you manage your participation? Do you get notifications via e-mail? How do you control how many notifications you get?
Do you read all the discussion, or only a subset of it? If you read a subset, what navigation hints do you use to help you find the parts you want to read?
Is the discussion overwhelming, or is it manageable? As an aside, I find that the Wolfram Community discussions become quite cumbersome at >250 messages in the discussion -- there's a limit that can be displayed on one webpage.
If someone has said something that warrants a personal reply (e.g., "Thanks!"), is it easy to send that personal reply? Conversely, is it easy to block receiving personal replies from someone who is too vocal?
Is it possible to block messages matching some keywords/user so that you never see matching messages in the future? Do you use those mechanisms?
Any other questions/comments in using Discourse vs. a Wolfram Community discussion for a course?
Thanks!