Why? Is it so they can switch in future?
I am (and have been for a while, not in a hurry) considering them each as a move off resque.
The main blocker for me with GoodJob is that it uses certain pg-specific features in a way that makes it incompatible with transaction-mode in pgbounder -- that is, it requires persistent sessions. Which is annoying, and is done to get some upper-end performance improvements that I don't think matter for my or most scales. Otherwise, I much prefer GoodJob's development model, trust the maintainer's judgement more, find the code more readable, etc. -- but that's a big But for me.
I've also run into issues where a db connection pool is filled up and solid queue silently fails. No error or logs, just stops polling forever until manual restart. Far from ideal.
But, I can live with it. I am going for minimal maintenance, and the ability to run solid queue under puma inside rails on cloud run is just so easy. Having ~3 solid queue related issues a year is acceptable for my use case, but that doesn't mean it will be ok for others.
Both MySQL and Postgresql could get their own optimizations.
I was responding to Rails not officially supporting good_job, though, which appears to be a Postgres-only tool.
That being said, I regret that we have switched from good_job (https://github.com/bensheldon/good_job). The thing is - Basecamp is a MySQL shop and their policy is not to accept RDMS engine specific queries. You can see in their issues in Github that they try to stick "universal" SQL and are personally mostly concerned how it performs in MySQL(https://github.com/rails/solid_queue/issues/567#issuecomment... , https://github.com/rails/solid_queue/issues/508#issuecomment...). They also still have no support for batch jobs: https://github.com/rails/solid_queue/pull/142 .