I had a long ordeal with my truck. Here goes.
Truck came with stock C rated Duratracs. They were loud but were pretty smooth. Few thousand miles in I started getting a constant vibration at anything over 65. Multiple balances later, still issues.
I figured maybe tires were bad. At this point went with Falken Wildpeak AT3W in E load. Horrible even after multiple balances, but to the tire's credit, I think the guys who did my balances did a horrible job and these were E rated and were going to feel rough no matter what.
Switched to Firestone Destination AT2 P rated. Again bad vibration and hopping even after two balances later.
Switched to Bridgestone Revo 3 in E load (Firestone wouldn't sell me the P rated version for some reason even though they did before) and out of all of them, these were by far the smoothest but still very rough and vibrations. 3 balances later, got rid of them.
Today I went to Discount Tire and tried their Cooper ATP in P rating. I think I finally found my tires. These so far (driven about 100 miles) are the smoothest and quietest out of the bunch, not to mention a lot cheaper.
I'm a little worried switching to a P rated tire, but I rarely tow, and I do go off road but nothing too crazy. Mainly fire roads around town. Hope I made the right decision, but so far I love them. I can enjoy driving my truck again.