What to say about Coursera, my first interaction was back in 2012. The most spread MOOC provider, brand for itself. Coursera is one of the best, maybe the best MOOC provider. In recent they started to force paid 4 certification method.
I agree with @Carolyn on her review. It's spot on, Peer assignments are really swords with two edges. But if you're writing anything relevant to task, you will not have any problems.
OFTP: I've noticed that most of the peer colleges, are thinking "inside the box". They're strictly bond to rules, they're not creative, at all.