D-mac1,
I've been RVing since 2002 and am on my 4th truck/camper combo. Always on a budget, I've had to buy used. Since I'm always looking for the "perfect" camper, I've seen hundred of used campers over the years. It has shaped my opinions.
Let's compare my 3rd truck/camper (a 9-1/2 ft Alpenlite on a SRW F350) with my 4th, and current, truck/camper (a 7 ft Jayco on an F150).


The Jayco has a much shorter cab over, and, it fits inside the truck bed -- no rear side end wings to catch water and road debris.
I've seen way too many older campers with flexing/hinging damage where is cab over attaches to the frame, and way too many rotted out end/side wings. A shorter cabover without end wings is a more robust, problem-free design than a long cabover with end wings. You do however sacrifice living space and storage space. It's an engineering and life style tradeoff.
Of course, this is the northwest. We get our share of moisture. Perhaps the climate in the rest of the country is more forgiving to truck camper designs.