My personal experience is that 4.0, 4.0 r1, and the Lite versions are easy to update,
but updating from 3.5, 3.51, and mainly 3,4F (that uses Beryl and only Portage, and is highly Gentoo directed) are very difficult to updating, and the system keeped stable!
Therefore, also more that 2000 packages can be updated!.
is much more easy and less time consuming, to backup important data and carried out a fresh install, and updating, because new GNOME and mainly KDE is much different from old versions....
also, new versions are better:: kernels, packages, execution, performance are much better in newer Sabayon Linux versions.
But for example, i have 2 installations of the 4.0 r1 version and one of the Lite MCE, that are fully update nearly 4.1, including new kernel and grub.
also, you may wait some more, since the nearly future 4.1 will be have complete support for new file systems, as ext4, in the boot.
If your Sabayon is sufficiently updated and functional, you may wait some more....
ALBERTO FEDERMAN NETOalbfnetoalbfneto@fcfrp.usp.brFavorite Distros: Sabayon, Gentoo, Mandriva and OpenSUSE