The average toy hauler isn't getting the QD's because they are heavier and more money which both hurt the toyhauler space where they are trying to stay under weight and beat the competition on cost. Would be nice if they were an option tho.
Inlaws have a onan QD in their diesel pusher and my toyhauler has the onan 5500 gaser non efi. Running side by side I think the QD is a bit less noisy. Between the two I'm not sure how they stack up on fuel consumption but oh my are you screwed over when you get the oil changed on them. The QD is nearly 3x the bill.
Not following the above post regarding running more items because its diesel; the wattage is still your limiting factor.