Having put well over 500 miles on my truck in the sand, I feel I can chime in on this one.
First of all. The stock NDTs are perfectly fine in the sand if you arent trying to climb steep hills. Once the grade gets to be more then about 12% they tend to dig instead of pull the truck. Most freeways dont go over 6% and we know how that can slow a deuce down on pavement.
Second. Airing down is a must if you plan on doing anything that isnt pretty darn flat. If I hit the sand with some momentum, I can keep the truck moving with rockhard tires(flatlands, no hills), while towing a 8,000lb trailer. Normally airing the front tires down to 15psi is more then enought to get ya most places. Only twice have I ever had to airdown the INSIDE duals on the truck, both those were trying to pull out 1tons with 40ft campers. I Have found if your doing slight hills, or may be pulling people out, airing the OUTSIDE rear duals down to 15psi works pretty good. When the inside tires dig down, the outside will float and keep the truck moving. I have never gotten my truck stuck in the sand, nor have I ever driven down into a place that doesnt have a semi-flat way of getting out.
Third. The engine just doesnt have enough power to pull this truck up hills in the sand, it generally stalls out in lowrange before it can dig itself down the axles. But just incase I always have a shovel, and 4 6ft Lengths of 2x12 incase I have to do the plank wood road if the sand is super soft. Have yet to have to do this.
Lastly, these trucks do great in the sand if you pay attention to your surroundings and don't do something stupid. Just remember, you can pull most things out, most things CANT pull you out. Also if you pulling someone out, use the weight of the truck and nylon tow ropes. The weight of the truck is more then enough to pull most things out, just becareful and let the person your pulling out hook the strap to his truck so if it breaks something not your fault.
If you have any questions feel free to PM me or ask here.
PS - I do plan on upgrading to 14.5s in the front, and 1100R20s XL's in the rear, to just get a little more float out of the front end.