With an air bag helper they are great. Make the ride alot smoother when empty. But when loaded they make the truck squat. Too much IMO. If you have bags to pump it back up level, They are an awesome product.
I ran them for 2 years on a 2007 F350 CCLB Dually. Towed everyday. They held up well. But i never got around to putting bags in that truck before it got retired out of the fleet. This was in 2013-2015, So they may have changed since then.