It does concern me a bit, and I'm thankful for this discussion, because in the near future I hope to be a 2022/2023 (whenever I get around to it) super duty owner. Right now towing a 9K TT, and probably something like a 12-13K fifth wheel in the future. for me, I've made the decision that a 7.3 F-350 makes the most sense. I don't want a truck that turns too many RPMs unloaded on the highway, but I also don't want it to lug while towing. Anything will seem like a huge improvement over my 4r100/3.73 combo right now. I guess it's first world problems when you get down to it. Anybody running 4.30s with a newer 7.3/10 speed, what are your RPMs on the interstate? Does it feel like it's too high? Anyone running 3.55 or so gears? Do you even use 10th?!?