agree, I was initially missing the "who's online" feature (although you can get to that from a different area) but there is the little green dot icon that shows who is online in the actual thread, so that might actually be more helpful than just the list of people that was on the old format. It's growing on me for sure.
I do think the posts take up a lot of room height wise, so there will be a lot of scrolling in this format if the same number of messages constitute a 'page'. But overall, glad to see the new format.