I've been told before that this advice isn't appropriate for anyone who isn't a Debian developer. Things can break and testing may not get important security patches until a while after unstable and stable.
Not a Debian developer here. I've been running both Debian testing and unstable on various machines for about a decade and it's been great.
In my experience, the "here be dragons" description of testing/unstable is way overstated... they're both very reliable. If you install apt-listbugs and `apt-mark hold` anything with bugs that sound scary, you'll be fine.
It seems like a lot of people try Debian stable (perhaps thinking of it as an upgrade path from Ubuntu), are surprised by the ancient software packages, and then look elsewhere. Debian might want to consider changing the recommendations they make for new users. Instead of stable / testing / unstable, they could be server / workstation / testing.
I think that having to check the issue tracker before installing packages is exactly the kind of thing that people are talking about when they say "here be dragons". By your argument, we would also be able to call Arch Linux a very reliable distro. It can be if you know what you are doing, but it isn't something I would want to recommend to the average user...
> Instead of stable / testing / unstable, they could be server / workstation / testing.
I would love to see something like that, but I think it would need significant changes to Testing to make it usable for the masses. Some years ago there was some work towards that direction with Constantly Usable Testing, which explains some of the challenges: https://old.lwn.net/Articles/406301/
The security patches is certainly a concern (though testing-security does exist, albeit not with the coverage of security-updates from stable). In my experience, testing is quite stable for 95% of packages; I can only think of a few instances in the last decade that testing has really broken my computer in a way that required me to break out my developer skills. More frequently, you'll find packages which can't be installed because they've been dropped from testing due to RC bugs -- but that's not necessarily a bad thing!
I've had a more pleasant experience using Fedora than Debian Testing.
Debian is great in general but the wonkyness surrounding the freeze period gave me the impression that Debian Testing really is something that should only be used if you are interested in helping Debian produce the next Debian Stable release. Some packages don't get timely updates and are only updated close to the freeze period, in preparation for the next stable release. And during the freeze period itself everything is super awkward because preparing the next stable release takes priority over keeping Debian Testing usable.
