Try to read some in here:http://en.wikipedia.org/wiki/Rolling_release
-> Thats the way you could have the system if you use Portage instead of Entropy, which is bassically "the gentoo's way"
And even inside Entropy, the release are in that way. 'Cause it has the same (or almost) apps but in binary packages only. If you don like the GUI (sulfur), equo should do great, but what are the needs in a GUI? Nice and shiny colors?
So, if you want, you'll hve a SUPER_BLEEDEN_EDGE system...
Just change the repository to use limbo ones. Make a world update (watch out, it's not a Debian Upgrade
) and feel Happy
BTW: the recommended space for sabayon are 20GB so, don't espect much less than that. But don't worry about the updates, when you reach about 8,5 or 9 GB (Which is the minimum required) the space stabilize it's growing...
Obviously, sorry for my poor English