I'm using 1.3 on multiple site's, on purpose. The biggest (also the most inactive one) is http://forums.audio-tracker.com/. The entire project that the forum belongs to, is experimental so I figured it would be a nice way to see how it's behaving in such an environment. No hard feelings if it breaks something. People would figure out quite soon I believe. And the sooner the better, bugs can be fixed faster and more accurate (when properly managed/submitted of course), I think. (due to inactivity and lack of time I haven't been able create any reasonable feedback, I got plans to do this any time soon).
<Smartys> I'm not sure why people think we're joking when we say don't use beta software in a production environment
<Smartys> If the software were ready to be used at that level, it wouldn't be beta
You couldn't be more right btw. I definitely wouldn't do this in case of a (semi-) large, money making, production environment.