The first two trips with my '14 GMC 1500 weren't much fun - white knuckle almost on one of them.. (I attributed them to wind) Same trailer similar roads and the new Cummins never got pushed at all.. Maybe the soft tires on the GMC allowed more movement? Maybe the heavier vehicle weight and E rated tires on the 3500 kept it planted? Maybe my hitch wasn't set up correctly (doubt that, double checked and same hitch i've had for quite some time, standard WD with friction sway control, etc..)
I've been a long time advocate of having enough truck, This is my third diesel with a half dozen other half tons mixed in over the last 10 years with this trailer and hitch setup thru 10+ states.. I'm not a full timer but have put in my fair share of towing miles as well..
My point was the Cummins 3500 feels PLANTED to the roads better than my GMC 1500 or the previous Dodge 2500 Hemi(which I used WD on) with this trailer as well as our other 14,400 GVWR GN living quarter trailer..