...WVa...going down a 6%, multi mile downgrade...places to bring the big horse trailer (17,000# GVW)..."pull the load and get it to highway speeds", ..."how well would it handle in an emergency maneuver on a steep downhill curve?" ...does not have the suspension or stability that the 3/4 and 1 ton units have.
A) I would take a very different approach to trailer towing IF I were traveling West Virginia mountain interstate. I've driven it many times and it takes effort WITHOUT a trailer. Clearly, that would make a difference in the discussion.
B) 17,000# is no joke. Very different discussion from 7,000#
C) I have performed an emergency lane-change maneuver towing my 24' Bayliner with only surge brakes and the truck performed brilliantly. That was a 5,500# load. Goober in a Geo pulled in front of me while towing home from the Outer Banks.
D) Ford rated the truck to 9,000#, not me. As a responsible adult male with children, I've pulled the rated load and WHEN PROPERLY BALANCED, it performed in a very controllable manner in acceleration, braking, and turning.
I always perform a "system check" which includes adjustment of my brake controller to the new load and a low speed 'emergency stop' every time I tow anything. I once loaded a
lower load poorly balanced and it performed horrible. I had to had some of the load removed and break out the shovel to balance the remaining load before leaving the loading area.
E) Traveling at or below the speed limit with rated load while making certain to keep ample room in front of you is perfectly safe and legal.
F) Traveling at 65 MPH with a 5,000# load in a 9,000# rated vehicle while generally in the far right lane, keeping pace with the semi trucks is perfectly safe and legal. See C.
G) Neither Note E or Note F requires a 3/4 or 1 ton truck. OF COURSE they handle a load better. If I towed a heavy enough load frequently enough or on extreme grades as you've described, I'd own one.
Please don't assume we're all unsafe morons. Not all suburbanites can justify or afford a 1 ton truck with gooseneck trailer. That doesn't mean we're going to kill everyone else on the road with our irresponsibility.
For that matter, a F550 is better for towing than a F350. A F750 TopKick better yet. We should all get one of those.
If you can convince my wife, I'm all about it...