Hi MNRon,
I'll add this which may help. My 2005 SRW F350 has a 7,000# rated GAWR-RR. It came with the LT275/70R18's LR E with Continental ContiTrac - TR's.
I am running my 3rd set of the Continental ContiTrac TR's. I am towing a TT, I believe you are towing a 5'er if I found your camper correct. And you have the diesel and I have the V10 gasser.
As far as towing stability, mileage, noise and ride, I have no complaints with the Continental ContiTrac TR's. But I did have a new issue on the 3rd set I bought, now close to 5 years ago that did not happen on the first two sets.
I on purpose would not change brands towing with a gasser (lighter engine) and a good size TT from Continental to Michelin's. This is my situation and yours may be different, you have the diesel and you run the front tires higher in pressure due to that I suspect. Mine is 65 psi for full front axle capacity and what I tow at. The rear's are at 75psi for the 7,000# rear axle. I need stiff front sidewalls at 65 psi to have a stable towing rig. The Michelins have a softer side wall and I got burned years ago with them on my K2500 Suburban running lower pressures even if it was full axle load capable. If you are running 70 psi or higher, with a diesel and a 5er, I suspect the Michelins will not be a problem for you, if you choose to go that route. But, I won't.
Now to the new issue that struck me on the 3rd set of Continental's and it was only the 3rd set. Those tires when new had some major squirm to them. I have heard others on 3/4 and 1 ton trucks regardless of GM, Ford or Dodge, having the same new tire squirm break in issue. And it was across other brands, not only Continental's, but this 3rd set was bad. I know it can take ~500 miles to break in tire tires, but it took until I reached 4,500 miles on them before the truck stability came back. It did sort of OK at 3,500 miles, but not still not the same as it as on the older Continental's. Heck, the 2nd set I bought (~ 5 years prior), I only had 300 miles on them and headed out on a 500 mile one way trip and thought nothing of it. But this 3rd set had some major stability issues. Something about the new way they mold tires, they can take longer to break in. Not sure what brands are better or not. It's a free for all. And I need new tires next year and I'll be thinking hard what brand to get.
The OEM Michelin's that came on my buddy's 2015 (I think) GM 3500 SRW diesel (same size and LR) pulling a big 5'er at full rear axle rating wore out in 30K miles. It seems OEM tires are now tweaked to give better ride and they give up miles of tread life to get it. The aftermarket same style tire can go the distance. So yes, new OEM tires can seem to be a good brand, but if it was OEM tweaked, they are suspect.
For the stability of towing a 5er, and you have higher front tire pressure, you may not have any issues with either brand.
Good luck with the new truck.
Hope this helps,
John