Fat tires inflated to moderate pressures absorb bumps really well, but still don't have much rolling resistance.
You can only run them at moderate pressures on wider rims though, and most bicycle companies are run by idiots nowadays who don't know jack squat about the stuff they're selling.
Big Apples will fit on a narrow rim @ 70 PSI, but they don't work right, and can't.
Get WIDE (35-40+ mm inside width) rims on your bike, get some 2.3 Big Apples on and inflate them to only 25-30 PSI and you'll finally understand how they're SUPPOSED to work.