Like Que said, LS is way more interesting.
>El Corona - Hispanic RP
>East Los Santos, Glen Park, Idlewood, Ganton - Black Male RP aka Guetto.
>Skate Park
>Basketball field.
>Mulholland, Richman, Verdant Bluffs > Mafia Roleplay.
>LSPD
>Airport
>Best business
So basically you can Roleplay whatever the fuck you want within Los Santos, that's why it is the main choise of the players, but move to other cities would be cool, for example Gvardia & Ancelotti, they are SF natural and they basically have to RP between them only, and if they want to RP with other players they will have to move to LS.
Same goes for the PD's, SFPD & LVPD are mostly used only when a suspect flews from LS...
So, there is good points in stay at LS(best for differents RP's) and move from it(giving other PD's and Faction more RP's).
I guess what you guys have to do is wait for RS5.