Yeah I ran the Defender LTX M/S on my 2500 and old 1500 as well.... but they don't make them for the 3500 dually.
I didn't really want the LTX A/T2.... so going to give the Agilis CrossClimate a try.
Picked a set up at Tirerack in DE, so I saved some on PA taxes & $96 for not shipping them.
With a bonus of filling the truck up with 35gal of fuel $0.55/g cheaper than it is here in PA.

I'll get them mounted up when it gets inspected and then see how they do.