Sweet looking truck. I picked one up two weeks ago, but haven't towed anything with it yet. I just traded in my bumper pull for a 36 foot fiver GVWR of 15500, which provided I keep the pin weight at around 20 percent should result in my keeping everything to spec. Like you, I got the factory airbag assist, but lost a couple hundred pounds of cargo capacity by going with the aisin tranny. Having destroyed an even half dozen transmissions over the year that has normally been the weakest link in my vehicles. I'm hoping that one is bullet proof enough to survive even me.
Keep it safe, and I can only hope I end up as pleased with my setup as it appears you are.