I can appreciate what you are saying about CV joints, but it haunts me that nothing heavy duty uses them. The same as nothing heavy duty uses torsion bars. I know the old Chryslers that used them (torsion bars) first were heavy "lead sleds", but nothing that is <B>really</B> heavy duty uses torsion bars or CV joints. Though front wheel drive cars do, but they have low GVW comparitively speaking.
And the CV joints fail under hard use, the same as U joints do. Get a rip in a CV joint boot, and not repair it ASAP, and the joint will need to be replaced very soon after. At a much higher cost than a $20 U joint. Granted, this is MHO.
As far as leaving torsion bars cranked up, many people think it's "OK" to do. Which we know is not the case.
I'm glad you pointed out they should be cranked back down after the season if one chooses to crank them up for plowing. Hopefully newbies will read and learn from that.
When I see CV joints on 4wd back hoes, and 5 yd dump trucks, and torsion bar suspensions on them, then I'll be convinced they are heavy duty.
Aside from the Powerstroke diesel, I feel that the solid front axles and leaf spring suspensions are a major selling point of Ford's heavy duty truck line. Again MHO.
~Chuck