Until recently, I have had difficulty keeping my 2350 dual wheels inflated properly. One of the valve extensions that came with the 2350S snapped off and left me with a flat. When that happened, I replaced the original ones with "airless" ones from Camping World. Those worked better but were tricky to adjust and one became unadjusted and left me with another flat.
I researched available solutions and installed some very robust, lifetime-warranted units found at: http://yourtireshopsupply.com/category/780_782/dually-valve-kits
for $120 plus shipping. They work! I have had them in use for a couple of months now and the pressures in all four tires have stayed within 0.5 psi of each other. The only changes in pressure are in line with temperature changes measured at dawn (expect 1 degree F for each 10 degrees of change since your last check). These units are not user installable; a tire shop will need 1-2 hours to install them. This may seem expensive, but a failed tire can ruin your life.
I just completed a round trip from NC to TX and did not worry about the tires. But, I still check the tires each morning before getting underway. The company that sells the extended valves also sells some metal caps with a built in valve at its tip. They allow you to check quickly your pressures without fiddling with screw-on valve caps.
Another subject: At about 20,000 miles I have had no problems with my 2008 Kumho tires.