I agree, JCM. If I had to buy gas, it would be a Ford V-10 as they have the best gas truck engine out there right now. With the 8.1 gone, GM & Dodge really don't have a truck-like engine. The way diesels are going, I'll probably go back to gas on my next new truck unless things improve with diesels. I'm holding out hope for 2 of the non-Ford brands to offer exhaust brakes on their pickups to decide. IMO, Dodge has the best chassis package right now, (Cummins/Ex Brake/Aisn/11.5" rear) but their future is so muddled right now that buying is out. Let's see what FIAT does with them for a few years. Besides, you can't get the Aisin in a pickup, must be chassis, but that works for me and my service body.
However, the V-10 is not a substitute for a diesel IF you're using a heavy duty pickup for its' intended purpose. The obvious fact is that the torque just isn't there. If it was, they'd be stickin V-10's or other gas variants in bigger trucks and they'd be outselling diesels, but they're not. It's not even close.
My FIL has a F-350 with a V-10 and it's a blast to drive empty, but when he hooked only an 8K trailer to it, you could really feel it back there. Not from a suspension standpoint, but when we hit the hills, it just downshifted & revved a lot and that's when they really gulp the fuel. If you had to tow heavy year round with the V-10, it would cost considerably more than a lower revving, higher MPG diesel, even if diesel costs 25 cents more/gallon. That's the beauty of torque down low in the RPM range-the fuel savings and longevity on the internals.
Glad to hear all is well with the GMC. The fit & finish, although thoroughly trashed by most, is just fine on my truck, too. I haven't had anything to complain about at almost 40,000 miles except my seat has a tiny squeak when you sit back a certain way. Have you had a chance to play with the Allison manual shift paddle? I use mine all the time and love it when towing. I can feather the gears with just a tap of the toggle switch, works like a dream for slowing the beast down!