[Wlug] gentoo

What's people's experience with gentoo? I'm thinking of upgrading one of my boxes to it in the near future. This is a box I really mess around with, so how bleeding edge can I get? Is it easy to keep some packages at stable releases, and some at unstable, or is it more of an all or nothing thing? I guess what I want is, a way of trying the newest stuff, but an easy way of going back to stable when I'm horrified with how buggy the newest stuff is. Also... for the stable releases... how secure has the distro been as a whole? Comments, horror stories, massive praise? -Marc