Oh boy here we go. I think I'll take an extra large popcorn for this one.
So I have owned two diesel trucks. My first was a 2009 F250 PSD with the 6.4 in it (crew cab, 4wd, long bed) that I bought in 2011. I had a lot of phantom issues that the dealership never could diagnose. It had a problem with smoking really badly every time it went into regeneration phase. It also had a very frequent regeneration issue. When driving g on the highway it would periodically have a loss of power that almost felt like someone had grabbed my rear bumper and tried to pull the truck back and then let go, it would only last a few seconds. Coming home from Disney, the gas pedal developed a really bad vibration and the truck had a loss of power. Again not able to reproduce for the dealer even though it did it several other times too. The biggest weak link on that truck though was it only had a 1500 lb payload. Yes that's a right, a 1500 lb payload on a 3/4 ton diesel. I also had to run cetane boost through every tank of fuel or it would void my warranty. Daily driving g netted me approx 13 mpg, towing g was approx 11mpg.
We traded the f250 off for a new 2014 chevy Silverado 3500 duramax/allison (crew cab, long bed 4wd) this past April. So far it has been a great truck towing and daily driver. Daily driving gets approx 16-17mpg and 11-12 mpg towing. As for payload, the door sticker on this truck was 4000 lbs available payload before passengers etc. (3280 lbs with people, pets, gear, 5er hitch).