If I had read threads like this instead of the specs for my truck, I would never have towed anything. I don't understand why a truck rated to tow 12K and a payload of 2000 lbs is not enough to safely tow a 10K fiver with 1700 lbs of pin weight even with fuel and family. My 9500 lb fiver is well below my 11.2K tow rating and my 1650 lb pin is, in fact, 550 lbs over the GAWR as measured on the scales. I added HD shocks and overload springs like Ford does for the HD payload option. In 12,000 miles of towing in the mountains of VT, NH and even WY, I have never had trouble with handling, stopping or going up a long mountain pass. I have never wished I had more truck for THIS fifth wheel. My F150 does double duty as a commuter vehicle for my daily 70 mile commute and that is why I got the F150 instead of a Super Duty.
That said, I now have an alternate vehicle for commuting, expect to RV more and my next fiver will be 4 season, so much heavier. I have ordered an F350 PSD SRW to deal with it. I expect to drive it a lot less because it will be less fun and cost more to drive, but it will be an even better tow machine. Today's Ford trucks are much better than trucks of 10 years ago, but not everyone is keeping up with that. I admit that prior to the F150 Ecoboost, no one made a truck that I wanted, but damn! this has been a great 1/2 ton!
2015 Half-ton towing