1) about:preferences doesn't work right (a known issue). I can't even bring up the applications list, and it doesn't even show up in the file handling tab of K-Meleon's settings dialogue.
2) YouTube videos are now choppy, whereas they're quite smooth in 75. This I was unaware of, because I hadn't tried YouTube in 76 RC. It's the same behavior I noticed in the latest Pale Moon (based on Firefo