Right, but you at least need to experiment with the other runtimes first before you can even determine whether there might be a good reason (like not having to

Right, but you at least need to experiment with the other runtimes first before you can even determine whether there might be a good reason (like not having to mess with tuning a bunch of GC flags anymore, one of the sells for Azul's proprietary JVM) apart from a forcing situation (like Oracle shedding updates and support contracts on their Java8 VM, forcing people to OpenJDK / Azul's OpenJDK build + cheaper support contract). In many cases it doesn't take much effort to spin up a mirror environment and see if the alternative "just works" and what its characteristics are apart from that. So my curiosity is really whether they found further issues with SBCL later, or if it's been a champ since, and if at any time they investigated developing with SBCL/CCL and deploying with (maybe developing sometimes with) Allegro or LispWorks (which at least if they hit new bugs with, they have a support contract to help). The thread from last year includes one report from another individual about swapping deploying with SBCL to deploy with CCL because of resource savings. I'm just curious in hearing about what trajectories people have taken.