One of my favorite jj features is "jj absorb".

For each change you've made in the current revision, it finds the last commit where you made a change near there, and moves your changes to that commit.

Really handy when you forgot to make a change to some config file or .gitignore. You just "jj new", make the changes, and "jj absorb". No need to make a new commit or figure out where to rebase to.

Oh, and not having to deal with merge conflicts now is awesome. My repository still has merge conflicts from months ago. I'll probably go and delete those branches as I have no intention to resolve them.