Bill D, one thing airbags would give those folks is the ability to raise the rear height of their vehicle, either full time or adjusted to different loads.
How much spring "suspension" is going to depend, in part, on how much load, how it's being carried at what height you want it to be carried. Light or heavy packer, short or long box truck, camper overhang, counter weight on front axle, towing pin weight, lift for clearance or appearance etc ... Lot's of variables for different setups for different folks.
And then there is the types of road you want to drive on. Bombing down a FSR you'll want enough spring rate to not bottom out but not so much you burst a kidney driving a pothole field. Highway cruising you'll want smooth ride but without wallowing in corners. Sometimes the "how much" will be "too much" and sometimes it won't. Like said above, it's a compromise.
Good news is, there's a lot of engineering in modern trucks and they do a pretty good job all round. Even empty a 3/4 ton is designed to give an acceptable ride and I'd say typically they do (others may disagree). And the factory payloads are not bad for carrying a pop up camper and some gear.
I'd suggest you determine what your current camping load is before replacing the vehicle. Even scaling the truck on a trip and deducting a curb wt found online would be a useful estimate. Then buying a truck that is rated such that your intended load comfortably within its own payload rating is prob your best bet for being in the suspension sweet spot.
One thing about factory leaf springs, the pack can often be reworked to better suit the application and owner. You should be able to find a truck and trailer spring shop in any major population centre that does this type of work. So if you get a 3/4 ton and find the ride too stiff you can have a leaf spring taken out, for eg, while still having whatever benefits the "bigger" pick up might provide you.
One last thing, my truck springs are so stiff I can barely push down the rear bumper with my own weight - maybe a 1/4" for a split second. But the rear drops a good 2" when the camper goes on. And when that camper is on the truck feels it: the diesel motor, the brakes, the suspension. All are effected in a manner noticeable to the driver. And when we're loaded for bear, that truck works !
So if this sounds different from other reports, keep that in mind when you read my comments. YMMV.
. All have an AL body.
