I like Jap cars and wouldn't own a domestic car! If I HAD to own a domestic car a GM car would be my very last choice (Well I may consider a Volt). That being said when I bought my tow vehicle I bought a 2006 Chevy Duramax after a LOT of research. When I set out to buy my tow vehicle I set out to buy a used Ford 7.3 Powerstroke diesel. I found that owners were way too proud of their 7.3 Poiwerstrokes and I could get a 6 year newer (2006) Duramax for just a little more than the Ford Powerstroke and get the much superior Allison 6 speed automatic with the Duramax.
I believe the Cummins is the best Diesel engine available but in the price range I was looking buying a Dodge Cummins would have almost certainly meant putting out many thousands of dollars shortly after buying the truck to rebuild the transmission. I believe Dodge now uses Aisin transmission which I have been told is pretty much a Jap clone of a Allison transmission??? A Dodge Megacab with 6.7 Cummins and Aisin transmission would have a lot of appeal to me! The Dodge regular crew cab does have enough room for adults to sit comfortably in the back seat IMHO.
The thing I DESPISE most about american cars especially GM's is the******electrical switches and buttons. In my opinion GM just buys the cheapest******switches and electricals... which the recent ignition switch recall seems to bear out my prejudices. When I had a Chevy Astro van I ended up replacing the OEM switches with OEM switches multiple times then finally replaced them with some quality metal toggle switches (window and door lock switches). HVAC, wipers and steering wheel controls I think you are just screwed. Other than the switches the Astro van was a tank and I loved... well except for the cheap plastic fuel injection spider that was designed to die after 100K!
That being said with near 200K on my Duramax all the door, window, HVAC, turn signal, cruise control, etc switches have "YET" to have a problem. (Several burnt out dash light bulbs though!)
I serously considered an Isuzu MPR truck for a tow vehicle but they are way to noisy and too harsh a ride. At least I ended up with a superior Isuzu diesel engine (Well Isuzu designed the Duramax diesel engine at least).
There is no way I would own a post 7.3 Ford powerstroke diesel. Every new generation of Powerstroke is the one they announce they have fixed all the problems in... but I wouldn't waste my money on one.