Muktware reviews Sabayon
and manages to summarise everything I like about this distro. Especially this:
Sabayon's repositories are updated weekly with the latest and greatest packages available. Because all Sabayon packages are built off of Gentoo, all packages available in Gentoo are also available in Sabayon (only in the binary (pre-compiled) format. As a result you get the cutting-edge stability of Gentoo, but without the time-waste or compiler headache.
In addition, Sabayon packages are about as close to vanilla (a term used to refer to the original experience provided by the package maintainers) as it gets, so expect a more pure experience. This means that Sabayon GNOME 3 is pure GNOME 3, Sabayon KDE is pure KDE, and Sabayon LXDE is...well you get the point. Most Sabayon distributions include the customization of the appearance of the user interface, but to ensure that the pure vanilla experience is provided, these customizations are done without modification of the packages the UI builds upon.