unfortunatly, i've the same answer as poke.
by experience, each version broke for some users while it is better for some others.
however, note that this is the result of limited tests for each versions ; only a view people are making tests during rc versions.and even if they do, it is a bit frustrating for them because it is no more time to solve minor issue that can have big impact, but just time to discover any big broken point.
the good point however is that batocera allows rollback to previous version without data loss.
i'm not ready for 5.21 ; i would like to release it in march, but i'm late on several points (and i'm taking most of my time on the odroid n2 these last days https://forum.odroid.com/viewtopic.php?f=179&t=33790 which is not a priority at all, but over priorities, i priorize my pleasure ;-)