Air ride might help, but if you're looking for it to ride like a caddy, or Towncar, you'll need to sell it nd buy a suburban, coils in the rear, and IFS in the front. Makes for a VERY unstable ride in the corners for such a top heavy vehicle . We rented on to drive to Vegas from here, and it was a sppoky ride at some points, tthrough the mountains
Its totally possible to make a Superduty ride like a Cadillac. Air suspension doesn't just help, its the total key. Its all about spring rate reacting to small bumps, suspension frequency and proper damping.
A vehicle with a certain suspension frequency will ride the same as any other with the same frequency be it a Cadillac or a Superduty.
Air bags are MUCH better than coils for a whole bunch of reasons. Adjustable ride height, progressive spring rate, increased spring rate with increased load (constant natural frequency), very low internal damping factors and outstanding high frequency isolation. To say nothing of how adjustable air ride systems are and I am not just speaking about ride height.
BMW uses air bags in the back of the X5 for a reason. Other luxury cars use them as well.
One thing that the Superduty has that no luxury car has is the ability to isolate the cab from the frame to further improve the ride quality. It also has big tires and a long wheelbase.