Not a fan of the new rounded corners on everything. Also, don't like how a repository's navigation is no longer aligned with the content of the repository itself. Just seems off.
Agree re the rounded corners. I think they were rounded before, but only two or three pixels maybe. Now with the greater rounding (which also forced them to increase padding to accommodate the rounding), it looks kind of cartoonish, rather than crisp and polished as before.
Other than those two, everything else seems OK.