My favorite thing about jj is that it takes the mental model of Git that makes sense (it's a DAG of commits, with references to some commits for metadata like tags & branch names) and just uses that. Instead of the actual full data model of Git which has several unnecessary complications like the index & mandatory branch names. It's much easier to reason about.

Tried jj several weeks ago... and absolutely love it.

A life non-goal for me is becoming proficient in a version control system and Git, insofar as I've been able to tell, demands that you become proficient in an uncomfortably large subset of its features in order to get through any workload, even in the simplest realistic cases.

jj did take some getting use to, but after a couple days it was all sorted and actions which terrified me in Git felt natural and safe using jj. The kind of things that required me to go back to the git documentation (or stackoverflow, or some blog posts) to be sure I was holding it right... in jj it comes easily and naturally.

That jj offers sufficient power under a simple interface to get through the day ... while being compatible with those that use Git... make it a no-brainer for me.