The Hub lets you run all Hogsoft programs from one small "stub" program, which remains loaded all the time. (This is one reason why PBII loads/unloads as usual, unlike PB v1.) It makes it much easier to run things like QuickMat. And with PBII you can switch banks directlyt from the Hub. (Also it is part of the P4PyE Python alternate, that supports plain old P4.)