In honor of you posting recognition of today's complaints, I've posted this using the beta. Even if some consider it pro forma at this point, here are some specific complaints:
2) White space and wasted space. Enough have made detailed complaints about this, so I'll just register my chagrin. I will say this: the people who come to this site are used to, indeed prefer, a denser presentation of information. This includes the text editor, which is absurdly restrictive on the x-axis.
3) Font size. Perhaps this falls under wasted space, but it's atrocious enough to deserve its own comment.
5) Absurd margins on the right.
6) Obnoxious or irrelevant photos. We're literate here. Many of us read books that go on for hundreds of pages without a picture. We don't need pictures added like some security blanked.
7) Load more? The old system gave preference to higher modded comments but did not require that you filter for higher comments to see them. Of course when there are a great many comments, a load more button is useful. But such a button should not be obscuring high ranked comments within moments of an article being posted.
8) I just found another as I went to "Preview Comment." Why does the p tag produce what looks like four lines of white space?
9) Above all, all changes should be subjected to this test: Do they get in the way of the conversation? Do they make it harder to scan through the conversation, looking for interesting comments. If so, they are not improvements. They detract from the reason people come to Slashdot.
The formatting matters are some of the most obvious and often discussed. They should also be the easiest to fix.