It's a good question actually. More people should put thought into their dependencies!
The latest non-beta version of both the editor and runtimes is generally the most stable and has the most fixes. Right when we move from beta to non-beta there may be some issues that we have to scramble to get fixed ASAP. We try our best to minimize that, but sometimes problems aren't apparent until after that move. Once a non-beta version has been around for a while, as 3.8 has, then you can be sure it is stable. 3.8 is our most stable release ever, especially since we recently fixed a few "mystery" bugs that we suffered for a long time!
The latest beta version, when available, has new functionality but you may not want to use it for production as it may have some features still under development, issues we haven't gotten to fix yet, and not all runtimes may have support yet.