We had installed Arch on a relative’s PC several years ago. It has performed flawlessly since – still boots fast and runs as expected. However, recently Gmail was not working in Chromium – when trying to log in, it would try and then just kick him back out to the log-in screen. Since we rarely update this machine, we ran updates, and then Gmail worked again in Chromium. This illustrates the principle we have been discussing – you are probably best off in most cases running the latest software. Bugs get fixed there first. And beyond bugs, there are hosts of integration issues between complex subsystems and not all these combinations are tested.
Backporting stuff requires huge amounts of effort. In some cases it’s needed, but my Arch experience has taught me that a rolling release is very practical, and for my use case, by far the best.