I have a '11 Silverado 2500 HD with a FWC and I *love* my rig. I've owned it since new, and will own it for the rest of my life. Mine has lived many lives over the years, from daily driver and occasional race car tow rig, to 40' 5th wheel tow rig, to it's current solid-axle-swapped exploration rig state. I think this is the "final" state of the truck, and hope to enjoy it like this for many more decades. My truck is deleted and tuned and has a 60gal fuel tank that provides amazing range. I'm not sure I'd want to deal with a newer diesel that from what I understand is much harder to delete (mostly because of the EPA going after small businesses and tuners) and all the DEF/DPF woes that go with it. I wouldn't want to be stranded far off-grid due to emissions stuff. Also, and it pains me to say this, I think the GM trucks are "behind" in terms of looks, interior and tech right now. IMHO the new RAMs have the nicest interior and both the Fords and RAMs look better (obviously that's subjective, and really is low on most of our priority lists). But the biggest thing issue w/ the GM trucks for serious exploration is the IFS. Now, I'm not anti-IFS in general. My truck was IFS 'til early last year and for all the other use cases I had IFS was superior. However, when it came to more serious off roading and the need for a front locker and more articulation SAS was the way to go for me, but it's very costly. If I was buying new for a FWC I'd probably be in a F350 single rear wheel (might as well get the higher CCC of the 350 over the 250, there's no real downside) with the 7.3L gasser, 10spd auto and leaf springs out back (unlike some of the higher trim RAMs like the Power Wagon that go multi-link, but have rather short arms and poor geometry). Just my $0.02.
-TJ