[bayindirh]

You're absolutely right, but that's one side of the coin. Debian also has matured its processes a lot, and they have a much bigger infrastructure now, so they patch tons of packages invisibly, and reproducibly build them, and I think some maintainers do their own suite of tests.

Debian 12 release is relatively new. Also we're in fall now. Package upgrade speed will take up in the next 12 months, reaching its top speed in 8 months if they keep up the usual schedule. I already can run two upgrades in a day, and get ~400 package updates in a couple of weeks. So testing is rolling pretty solidly now.

It's a bummer that security service for testing is discontinued now, but it's only natural. The project got too big, and the attacks are evolving faster than ever, so security people have so much time and staff to handle this.

I didn't experience any ABI compatibility problems with closed source or external software with Debian testing. I'm running Pagico, InSync, StarUML, etc. which are Deb packages and all of them are built against Debian stable or Ubuntu. They work without any problems. Well, Pagico needs libjpeg, but that's another thing unrelated to ABI.