I've read different theories on 16" vs 19.5 ride quality. One thing was that a 16" E rated tire aired up to max psi for load will ride harsh compaired to a 19.5 aired much lower but still handeling the load.
It depends on how much load they are carrying.
I run highway / all-season E's at, or near 80 psi cold on dry or rainy days all the time; only drop them when it snows or I need to cross soft turf. The heavier (~7,500# and 1 ton suspension) rides and handles like a firm sports car when empty. When I put the trailer on it (~700# tongue) and stuff in the bed, it rides and handles like a sports sedan; not harsh at all. The Burb (8,600# suspension) rides pretty much the same way.
And to get ahead of the 'you will get abnormal wear with 80 psi' comments, no this is not my experience at all. The treads on the highway / all-season tires end up wearing out pretty much evenly even when running at the max cold rating.
I did sell off a set of load E A/T's to a friend with a 1/2 ton GMT400 as they were simply to squishy for my taste. On the friend's truck, he had to lower the pressure down to 50 in order not to bruise his kidneys. So, yes the same tire on different vehicles will get a completely different ride.
To come full circle, my vote is to go with the load E's and then pressurize them first to the weight rating and then to personal comfort. Intuition is telling me that with the camper in the bed, you will tend to work your way up toward 80 psi in the rear and at least 65 in the front.
I called, they are marketing the wheel/tire more toward trailers as an up grade from 16.5 trailer wheels/tires. The 19.5 is rated for more weight than 16.5
