> One of the unsung praises of Arch is that it's turned thousands of users into testers.

You can do that well enough with Debian's "testing" and "unstable" release channels. Aside from the few months leading up to a new "stable" release, which usually isn't a big deal (and fixing regressions in "stable" should then be a higher priority anyway). Just don't install it on systems that you actually depend on to keep working. But running it on your desktop at home that you only use to play and experiment with is just fine.