I would like to wade into the air pressure / clearance topic. Simply put the small decrease in clearance is more than offset by the increase in traction. And like the others have said the other benefit is a smoother ride. We have a rock trail that we run here summer and winter - as long as the snow doesn't get over 2 feet deep. The entrance is beside an old granite quarry. With snow approaching 2 feet in the deeper spots I could get about 15 feet up before spinning to a stop. Thats with 25psi in the 35 bfg mt's. Airing down to 10 psi the Jeep made it all the up the hill and pretty much over the trail the whole day, although a winch is still needed in a couple of places due to steepness and slippery icy spots. We did have a young fellow in a basically stock YJ with 31,s who was also able to follow us aired down, he did need a pull every so often though, you should have seen his face on one pull, we had just crossed below a drifted in beaver dam and even with 3 of us breaking trail he did not have the clearance so I hooked a strap to him and since there was a fairly flat stretch after the dam I gave him a ride at about 25 mph hooked up to the strap. He was laughing so hard when we stopped he could hardly stand. As far as rim size I have used my 35's on both 8 and 10 inch rims and they both work.