[Sammus]

Well it has to do with the shape of the launch, not the truck. See the difference hitting the same jump holding the throttle pinned over the lip compared to accelerating then letting go half way up the launch. First one you will nose up, second time you will nose down. Nothing to do with how the truck is set up, just simple physics. If you race on a track your not used to you might not be able to hit every single jump perfectly at the perfect speed, and by using the throttle and brake you can exploit the conservation of angular momentum to adjust the angle of your car in the air so you land the jump nicely.

With 'soft start' air esc's you can't blip the throttle to nose up if you hit a jump off the throttle and nose down a bit in the air.