We just flipped the switch today in anticipation of the July 20 "enforcement." The default view, particularly the extra clicks to see replies, reminds me of YouTube comments. It seems that, as with many Canvas updates, Instructure was going for aesthetics over academics. Sure, on the surface, the redesign looks cleaner by tucking the replies away behind extra clicks, but for the students and faculty who have to actually read the posts and provide substantive feedback to each other, this is counterproductive and will result in even less engagement than before.
Also, the font size in the replies is smaller, so if you are reading a reply to a reply, you better get your reading glasses or a magnifying glass. This issue is present whether you use the default in-line view or the split screen view. I figured maybe split screen would at least retain the same font size, but nope - still small. The right-hand panel in split screen view is similar to how a rubric displays in SpeedGrader, but unlike SpeedGrader, the panel isn't expandable. Maybe if you could drag it out to the left more, that would increase the font size.
The main issue we have is the default order displaying newest posts first. Our discussion prompts are built into the course, so faculty typically make an initial post by replying to the built-in prompt. Their initial posts provide students with additional instructions, links, videos, and other helpful resources. Those are getting pushed down to the bottom by default now, so we're advising students to use the Sort button to flip it to oldest-to-newest. There does not seem to be a way to change this at the account level.