I played with mine when I first got it, I seem to remember an inch or two being a lot - that's maxing one side and dumping the other. I carry 2x6 planks that make far more of a difference then 0 psi vs 100 psi.
2007 Chevrolet 3500 CC/LB Duramax/Dually 4X4 Mine r4tech, Reese Signature Series 18k +slider, duratrac, Titan 62 gallon, diamond eye, Cheetah 64
2011 Keystone Fusion 405 TrailAir & Triglide, Centerpoint, gen-turi, 3 PVX-840T, XANTREX FREEDOM SW3012, G614