Entropy is a complete binary package management system, it does remove unused dependencies. It is NOT a front end to portage, the packages are binary, i.e. you don't compile yourself, this mean quicker downloads and much easier management, but you also loose the ability to customise and optimise the application like in Gentoo.
The forum posts cant be used as judge as the "Equo/Spritz" forum was only set up about a week or so ago while the other one "emerge" has been around for a while and has been renamed.
Personally, I mix both, I prefer to use Entropy as it is more reliable IMO but portage often contains newer versions, if you are new I would highly recommend trying out Entropy (via the Spritz GUI).
But again, opinion on which is better varies, try both, if you disliked portage before, its exactly the same on Sabayon, but you could use entropy.