In the last 20 years I've had over 25 heavy duty pickups. In the 90's Dodge had the only good diesel motor on the market, their transmission, brakes and suspension really sucked. The Ford Powerstroke wasn't in the same league and Chevy was a joke.
In 2001, Chevy came with the Duramax and Allison. Great engine and transmission. Surprisingly the Chevy suspension also led the pack. Proves you don't need to jack them up in the air to have a good suspension.
Currently, all three are very good trucks. Ford has fixed the Powerstroke problems, Dodge has a much improved transmission and brakes. Chevy has improved the Duramax.
Currently, I've got 4 Chevy ton dually's with the Duramax and Allison that we use the crap out of on the farm. I think I will try a Dodge next, they are more willing to deal than the other two. I've been around diesel's a lot and the Cummins is definitely a great engine, even my John Deere lawn mower is a diesel. The only gas engines I've got are 2 Harley's.
If you really want to pull a load, there is no comparison, buy any of the big three diesel's.
Cowboy