Among so much else, I liked seeing the other side of Simon in this episode.
As he’s such a fish out of water in the situation of Serenity and so deferential the majority of time, as well as not really seen as fully engaged with the crew as a member, seeing the collaboration, leadership, and in-hospital authority and backbone rounds him out more… and also gives more insight into just how much of his life/role he changed to get and continue to keep River safe.