[takluyver]

Technically, Debian unstable is close to what I want, but I don't want to be using something that comes with 'at your own risk' warnings day to day.

I think the expectation is the important thing: if an update breaks something, the response I want to see is 'sorry, we'll fix that ASAP and try to avoid doing it again'. I get the impression that Debian unstable (and to a lesser extent testing) is only intended for people who're willing to put up with things breaking often.

[icebraining]

Well, yes, it comes with absolutely no guarantees. That said, many Debian developers use it, and breakages have been rare at least for the last few years, since I started using it.