I put Air Lift 5,000# bags on my 24' Class C when I started towing my 6 X 10' {8' tall} cargo trailer. I typically haul either my Can Am Spyder or my Polaris Rzr SXS with the loaded trailer coming in between 2,200 - 2,600# depending on what additional toys I load {my coach with the 6.8L V-10 us rated to tow 5,000#} so I am nowhere near my theoretical limits.
The whole purpose of the air bags is to ensure that the loaded/hitched trailer tongue is dead level with the ball exactly 16" from the ground to the top of the ball as per the trailer manufacturer's recommendation. For me that requires 50 psi in the air bags. I keep 25 psi in the bags when not towing per Air Lift's recommendation to prolong the life of the bags as they do not do well when completely deflated. The bags will take up to 100psi but I would never have enough of a load to warrant that much pressure.
At a full load and 50 psi the coach rides and handles just fine "almost" like the trailer is not even back there. The coach has always had great ride and handling characteristics and I was surprised that when not towing running the 25 psi dramatically improved the ride overall which I was not expecting, but do love... go figure. :h
Here is a short of the rig:

:C