I just came back from a mineral exploration job on forestry roads. Logged about 1000 miles with my DCLB with dakars and airbag carrying my ATV and about 400 lbs of rocks and gear on dirt roads (probably overloaded by 300 lbs). I did weld my own airbag spacer (see pick, a pair of 1 1/4 inch square tubing just below bag) to compensate for the height of the Dakars. I added 45 PSI, the ride was stiff but good when hitting washboard and ruts at 50-60 mph. Not too bouncy in washed-out trails either and flex seemed good. Small changes in PSI makes a big difference in how the Taco handles the load, it takes a few tries to get it perfect.
As a side note, my truck deck has now handled over 2000 miles of rough dirt roads with an ATV or snowmobile on top. It's great not having to worry about a trailer in the back, especially when entering really tight roads.