I am currently using Ubuntu 20.04 with the Sabrent Rocket M.2 SSD and AMD Ryzen 3900x and several times my OS continiously locks up some programs for a short time (Chrome, Firefox, etc.) or becomes really slow. This computer I built is relatively new and used for work mostly so I am not sure if it's Ubuntu or I downloaded a stray snap package but man I have noticed Snap packages can be ... slow.
I used Debian and it seems to be gaining detractors from Ubuntu, my only question is... what made you switch and sick with Debian?
I suppose I'm used to apt-based systems, although I don't know if it really makes any difference. So many other distros are based on Debian, but often it seems like a pretty thin layer, perhaps poorly maintained, over Debian itself. Debian seems to have so many more developers, so why not just use it directly.
The rough edges I've found: no automatic updater or security updates in testing, just run apt update/upgrade once a day. An initial problem with the video driver not working because it requires non-free firmware, solution is just to add Debian non-free (it would have been helpful if a warning was given during installation). Firefox/thunderbird still on an old long-term-service release: I've been installing tarballs manually for now.