The main difference between mise and pixi is an ability to subscribe to conda channels and build (in an extremely fast way) conda environments, bypassing or eliminating most of the conda frustration (regular conda users know what I mean). mise allows to install asdf tools primarily (last I checked).

On the python front, however, I am somehow still an old faithful - poetry works just fine as far as I was every concerned. I do trust the collective wisdom that uv is great, but I just never found a good reason to try it.