I just installed an airbag suspension on my new '15 F350 dually and took it on the first camper trip. I will put at the end of this post the reasons for doing it to save the long narrative for those i...
I disagree with the comment that safety or reliability is why OEMs don't use airbag suspension. Have you looked under a Peterbilt? Most real trucks do ride on factory air suspension.
If your airbag overloads give you sway, my first question is whether your left and right bags have separate, isolated air supplies. If your shocks are good and you've got a rear sway bar and air bags, you should be fine.