"testing" is probably the worst choice. It's auto-generated from unstable with a 10 (iirc) day delay if no critical bugs are open. However, if a critical bug is

"testing" is probably the worst choice. It's auto-generated from unstable with a 10 (iirc) day delay if no critical bugs are open. However, if a critical bug is fixed in unstable and another one found that affects both unstable and testing, then the release fixing the first bug won't migrate to testing, so you'll have an even more broken version for a longer time. Testing also receives no security updates. Unstable doesn't get security updates either (in the sense that the security team doesn't provide updates to unstable), but it usually gets fixed versions pretty quickly, and certainly before testing. "unstable" with apt-listbugs installed works quite well for me. Sometimes I have to boot grml to roll back packages (check out the grml-rescueboot package), but that's very rare.