joel not everyone drives/races a gtr....only blokes with no skill require four wheel drive. Real men drive gtst's!
the slight response difference between the twins or single isnt that big of a deal in most cases...maybe if your racing for sheep stations. In almost every circumstance you can offset it with something else that will make your car quicker around the track or on the street. As is the problem with most people is the cost involved in it all. Twin setups will always cost more then single.
VHR32 - ive raced with a .82 rear gt35r and i think a 1.06 rear would be better for control, but the lag side of things would outweigh the benefit of the control. I would rather then extra response from the .82 and control the power better with my foot, not only that but having a disadvantaged mechanical setup teaches you to be a better racer as it forces you to adapt rather then just relying on a more superior setup to improve your times/position.