Again. Stable is for servers, testing is for personal use.
I never argued otherwise, ever.
However, while Testing is "relatively secure", it's never "Server secure". I'd never use testing or testing packages in stable or any server for that matter.
I have to add that for me, testing definitely breaks stuff sometimes. Nothing beyond my ability to fix, though. Nothing beyond anyone's ability now that AI is around.
That's interesting, can you give an example? Asking as a curious Debian user.
However, one thing that many people don't know is that Testing enters a package freeze every time a new Stable release is to come out. And this freeze can last anywhere between 4 to 7 months. So for that time period, it stops having frequent updates and becomes essentially a stable distro.