We run them with independent in cab pressure control & compressor kit - works great for leveling the truck camper side to side when parking. Hauling the toyhauler I'll run enough pressure in them on normal roads so the truck is not engaging the overloads. Nice ride. On "frost heaves" roads I drop the air to allow more overload spring engagement which settles down the "hobby horse" motion of the 5th wheel. I am adding Stable Loads from Torklift to engage the bottom overloads earlier.
The toyhauler pin weight is about 2800lbs.
The air bags are the bee's knees for hooking up to trailers with a minimum of cranking of the landing gear.