When attempting to update packages through ssh, I get "E: Repository 'Index of /raspbian buster InRelease' changed its 'Suite' value from 'stable' to 'oldstable'" which makes sense since Bullseye replaced Buster. Is it a bad idea to update to Bullseye? This is a fresh Octopi install, my old had had the SD card fail, so any issues wouldn't cost me my configuration since it's already gone.
I'm running OctoPrint 1.6.1 and OctoPi 0.18.0 on a RPi 4.
I would recommend staying with buster for the time being. I had the same thought when I saw the suite change, but after trying some things out after upgrading to bullseye it would appear that some packages are in flux and things may not be stable yet.
Notably, the package that installs the development files for the HW OMX encoding has changed the location where it installs and even seems to be missing files. This may not impact you, but if you are using the HLS webcam streamer instead of mjpg-streamer, it probably will. See my issue on uStreamer for details:
There also seemed to be some weirdness with wifi being disabled upon bootup, but I'm not sure if that was due to upgrading or something else I had going on.
I imagine that when things are ready bullseye will be the default for new images...