I am torn between sapling and jj. Both make good progress in git/github integration which seems to have been the major road block in adoption before. One other major roadblock seems to be the limits of review tools supporting stacks: github PRs are too limited, gerrits ux is horrible, graphite does not work and is not open enough, saplings review tool is just a very slow performing POC (though with a really good UI concept as starting point)
for me important argument in favour of JJ over Sapling was "first-class conflicts" - JJ stores conflicts in the history and allows you to resolve them later, while Sapling forces you to resolve conflicts at the point when they happen
If first class resolution is done right, then instead of project generators we can just create sample projects that people fork, and when you make breaking changes or add new startup config to the project, you update the sample project(s) and people can pull the updates. Once you resolve the conflicts you’re done until the next change, at which point your repo remembers how the last conflict was resolved, and doesn’t ask you to redo it.
This is why jj is on my todo list. I’m not calling it jujutsu no matter how much someone pays me though.
Gerrit, as I like to say, has a user interface that only a mother could love. But ultimately it's a very productive tool, so I just got over it. I even wrote some integration between jj and gerrit, making submitting stacks very easy and smooth.
IMO, Gerrit is the best currently available option by a large margin, notwithstanding its quirks.
graphite only works with graphite tooling. you cannot just use sapling or jj to create a pr on github and then use graphites review tool, even though this should work in theory, but they block this somewhere in the pipeline.
