Mine is an '07. I have not had any issues. It is stock except for an aFe air filter, gutted intake tube and a 4" hole in the bottom of the air box. I have been running with the EGR unplugged for about 60,000 kms. The truck now has 80,000+ on it. I did try a boost fooler on it. I found that it would trip the DPF full message. Took out the fooler and the problem went away. The truck has been to the dealer twice since new in January '08, once for the firewall recall and once for a reflash to AB.
I just completed a one week, 7484 km run to Ontario and back. Going down, it got between 19 and 22 mpg running empty. The best mileage was on the prairies at 120 kph / 1900 rpm. Coming back with a 1500 lb load we were pushing an 80 to 90 kph head and side wind along with rain and snow for most of the way around Lake Superior, which dropped the mileage to 16. On the prairies again it was back up to 19. I think she did pretty well.
As has been discussed here before, to help these trucks, one must keep idle time to a minimum, keep the rpms up and use the engine brake at all times.

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2007 Ram 2500 QC 4x4 SLT TRX4-Offroad 6.7L Automatic. '08 Jeep WK 3.0L diesel-wife's DD.
1998 Jeep ZJ 4.0L Automatic Selectrac-project for our son. '98 Jeep XJ-my wife's former DD.
1965 Dodge Polara 880 Convertible 383 Automatic.