It's absolutely great for keeping a bunch of exploratory changes alive, quick prototyping, etc. as I tend to do with basically every source I have on my machine. I don't have to think at all about the stuff I hate about git (babying the index, being careful to amend and etc. right the first time because undos are annoying, etc.)
Does not support LFS or submodules though.
We still use submodules in a number of places at work so it’s a bit of friction for me. Other than that, I’m rapidly becoming a jj convert.
It actually works quite well and has never caused me any issues. I tried symlinking but that does not work, git doesn't like the .git being a symlink.
Relatedly, when I use filesystem paths as remotes they need to be colocated or else it doesn't work, which is a little annoying!