I trade-in my F-Series Crew Cab every year. I used to tow a 24' all-aluminum Gold Rush, but I just took delivery of a 24' Sundowner.
When Ford introduced the aluminum F-150 in 2015, I bought one. A friend of mine, who was an engineer at Ford, pushed me to get the EcoBoost TT V-6 in the F-150. He told me that the EcoBoost TT would haul like a locomotive... which it did! I tow my cars about 23K-25K miles per year. I can tell you that the EcoBoost had no problems towing at all... including through the Grand Tetons and Rockies! In the middle of the country, I will run about 75-79mph. At this speed, and with the trailer loaded, the EcoBoost was getting about 6mpg. The gas mileage was my only complaint, but then I didn't buy the truck for its fuel economy!
In 2016, I decided to try an F-250 diesel. My mpg jumped to 11.5 when towing at speed. I have never had any problems to speak of with any of my F-Series trucks. Sure, I only own them for a year, but they are getting relatively heavy use.
The power wars among Ford, GM, and Chrysler have resulted in trucks with insane torque numbers. My 2019 F-250 was nuts with 935ft/lbs. My 2020 has 1050ft/lbs, making it difficult, at times, to pull away without spinning the tires.
I took delivery of the 2020 F-250 about two months ago. Because of COVID-19, the truck has only just over 5K miles on it. It is probably still too early to tell, but the 10 speed is just fine so far. It shifts a lot, but it has almost 70% more gears to run through than the 6 speed did.
I will report back if I have any transmission issues.