Quite the contrary, it aged extremely well. Debian testing/sid is very usable on a desktop/laptop; I've used it successfully in such fashion for something like a decade. Nowadays I do prefer a distro/OS with a 6-month release cycle (like NixOS or OpenBSD), but as far as rolling releases go, Debian has always been great.

What are the advantages of using Debian testing/sid rolling release instead of a regular rolling release distro (say, Arch)?

Debian Sid is the original rolling release. Its advantage is is that you are on a rolling-release distro but it's still Debian, so all the system knowledge you accrue will apply seamlessly to production Debian servers. Most rolling-release distros, on the other hand, are typically not used on production servers.

Also, packages are tested in sid/unstable and migrates to testing which then becomes the new stable when it's ready.

And packages are tested across releases, enabling one to dist-upgrade to a new version of the system easily. I think it's piuparts that does this job of testing packages among themselves too.

Sid is not a rolling release. This is a common misconception.

In preparation for a new stable release, it goes through what is effectively a package freeze. Maintainers are discouraged from updating packages in Sid in order to focus on the new release. So almost no new updates are uploaded to the repositories until Stable is finally out.

That's not exactly a hard rule, just stuff maintainers do because it is far easier to still have normal flow of unstable -> testing for the freeze period, and keeping 2 ("actual unstable" + "unstable on the way to the new release") would be a big burden for maintainers.

Correct. This is why I said “effectively”. At the end of the day, Unstable does run behind during the freeze period. Same for Testing, obviously

Like toyg says, I really enjoyed having a familiar working environment both on servers and on my workstation. When big changes would come around (like the transition from SysV init to systemd), I'd start getting hands-on experience early, and upgrade production with more confidence.

Between testing/sid/experimental you also got the choice of running "somewhat stable" vs "bleeding edge"; I'd usually stick to testing (except around the freeze leading up to a release).

Most Debian users are advised against using testing and should use Sid instead if new packages are neeed https://www.debian.org/doc/manuals/debian-faq/choosing.en.ht...

What's irregular about Debian, and why would I use Arch instead of it?

I rather meant irregular with regards to Debian Sid not Debian in general.

Arch only has rolling release mode so everyone is using the latest (thus any potential issue in Arch will affect bigger % of Arch users) while Debian has stable and testing and I was wondering if that'd make Sid less stable for practical use (since "it's not stable").

I don't want to start a distro war here, just wondering about some anecdata of actual distro users.

Anecdata, if you aren't advanced user with new hw, Sid might be more robust, otherwise Arch is superior in almost any way. I wish it wasn't, I like Debian community more, it is less elitist.

I'd think that both distros work with upstream as much as possible when bugs are found. I'm too lazy to do it, but you could check both distro's bugtrackers for activity to know if one really generates more checking than the other, but I'd be surprised if in practice there's a big difference. Maybe pick a few packages, see how fast fixes are merged?

It would have been fair to say it aged well, if the version which is currently called testing was their flagship version.

For most software, the testing version gives you relatively latest stuff. But that doesn't mean every software can advertise itself as being up-to-date.

For debian specifically, I don't think they recommend using the testing version unless you're a Debian contributor/tester.

I've tried using Sid (desktop) in the past, but ran into several version issues while installing through apt. Didn't try much to debug, and switched to stable. Been a happy user since!

And happy 30th birthday to debian! Really appreciate all the work and effort that has gone into it.

In my experience 'sid' is what you typically use on desktops, 'testing' on servers you actively maintain, and 'stable' for servers that you just want to keep running without much fuss. 'sid' can have some interim issues, but nothing significant enough that it would disqualify it from desktop use; and 'testing' is really solid already for those who don't feel like power users much.

Sid isn't a rolling distro in a general sense

It has aged extremely well. Based on the degree of the up-to-date you need you can use

* Experimental

* Unstable/Sid

* Testing

It all depends on what your definition of up to date is.

Switch to unstable.

There's always RHEL :D

Well, you might think that if you know nothing about Debian. I recently was debugging kernel bug and to check whether it still happens in latest mainline I just... installed package directly from Debian repos.