I used it for a few years, great distro. I think it's dead now. It was based on Gentoo but with thoughtful defaults and a very good binary package manager.
I used Sabayon for a bit too. It was basically "Gentoo made easy" with a simpler installer and as you said a binarypackage manager rather than compiling packages from source. It's wasn't 100% completely dead after dropping the Sabayon branding, it morphed into Mocaccino Linux, but when they did so they re-based it on Funtoo, which is also now dead.