My 2 cents... I have ridden in CA for years and really came to appreciate the ability to split lanes. But after moving to a place like KY (people on 2 wheels here are appaling to me in their skills and sensibilities) I think that people who havent been able to do it at all suddenly becoming able to would cause one heck of a mess. The people here dont wear helmets and pull wheelies in rush hour around town and act the fool, cant imagine if you gave them a reason to act even cooler by passing cars.
The main benefit I saw to splitting was on multi lane roads with tons of lights, you get ahead of 10 or 20 cars per light and dont have to wait 45 seconds to accelerate to 45mph. Even more helpful in smaller cities that dont have 743253245 freeways with all 8 lanes clogged like around LA and San Diego.