My main dislikes are slow, lazy loading, and that you can’t read the last commit messages without extra clicks of the “...” button. Even in pull requests I’ve seen new commits show up without the message (and clicking the expand button, it closed itself after a few seconds).

There have been some other annoyances/changes in behaviour that have bugged me too, but mostly stopped remembering them because am resigned to it now.

the repo top bar is wider than the rest of the content. It feels unbalanced. Personally I'm not a fan of that part. No complaints about any other change.