kGo has 510 and eGo threads, hence the "Go" part of the name.
You are correct. The eGo (and KGO) uses an eGo connection. It is not the same as a standard 510 because of the cone threads. Clearomizers like the Stardust (eGo Vision Clearomizer) screw into those threads (and others require at least a recessed 510 to even connect). That's why APV users generally have to get a 510 to eGo adapter to use them. The eGo connection is superior to the 510 connection because it is more versatile and you can get collars/sleeves/mini cones to cover the threads for dirt cheap if they are not used and being exposed bothers you.