I also have the issue with the taskbar sometimes not disappearing but I've had the same issue on Windows 10, various Linux DEs and macOS. It must for some reason be a more difficult problem than it would seem.

The biggest issue I have with Windows 11 is that the taskbar can't be moved from the bottom without a registry hack. I find the biggest UI improvement to be in the file manager.

I also find the whole thing to be a little better performing than Windows 10.