I did an in place upgrade and the only thing that I noticed that was different was all my custom fonts I installed were missing, everything else has been a flawless transition
I've tried Windows 11 multiple times and the multitude of technical issues I've ran into and inability to modify the default UI have pushed me back to Windows 10 - every. single. time.
Issues include: poor Bluetooth support(audio cutting off at the start/slow to activate), bad VM sound, lower framerate in certain titles, unnecessary bloat, ect.
Also Microsoft slapping so many ads everywhere they can: Start menu, Explorer, Bing on the Taskbar, Account controls..... it's just insulting sometimes, even if the upgrade is "free".