For me, the change in font hugely hurts readability. Segoe UI is very thin without much letter spacing so maybe a slight increase in font sizing or a change to other base fonts like Noto Sans or Helvetica Neue (referencing other forums or text-focused websites like Reddit) would help sort that out.Most places definitely look nicer, but a lot also took a huge hit on readability. For example, the reputation page is much harder to read and understand what is going on than prior, with huge gaps between reputation, no clear green/red indication on type of reputation, and sudden shifts in the color scheme.
Threads also took a huge hit in readability, instead of each comment being attached to eachother with a fine divider between, there is now a margin and blue line above each comment. While this seems like it'd seperate and distinguish messages more, it, to me at least, makes it feel much more cluttered and harder to follow along
