Probably not too much of a difference. I'd imagine you'd probably get a little more flex with the new springs though. If Rusty's springs are like most other lift springs, they will most likely also firm up the relatively plush stock ride. A BB may not make the ride rough, but it won't firm it up either. Either way, shock selection (limiting travel), disconnecting the front swaybar (assisting wheel flex), and changes in the trackbar will have just as much of an effect on offroad perfomance. If it comes down to price, just get the BB. If price is not an option, go with the springs/shocks. Either way, chances are once you see you're jeep lifted, you'll want both the springs and BB in there.