The only annoyance I had with the stages in SA2 was that it felt like the Dark story had too many Eggman stages and not enough Shadow stages, or at least the Eggman stages were too long and the Shadow stages were too short, where the Hero story felt more balanced.
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.