Depends what you are hauling/pulling. If you need the maximum load for the tires, then you need to run the max pressure. You will NOT feel any difference in the ride quality- on a 6000 lb truck, sonene can tell me their *** can feel if a tire is 80 PSI vs 60? Doubt it.
I have been running my P rated at 44 PSI for 2+ yaers now- no extra wear, no rough ride, and I may be getting a little better MPGs than the same truck running 32 PSI.
The dott sticker is published based on the OEM tires- P rated, I assume. Its in valid with E, LT or any other tire not OEM'ed for that model.