I have the 3.7 with just over 80,000 miles. it runs phenomenally considering the amount of torture ive put it through. It does lack power and torque. however, it is a reliable vehicle. the 4x4 to be quite honest should be used strictly for
what it was designed and not mud running. I get just over 11 miles to a gallon, which is disappointing but, again this thing just keeps running. The only real issues Ive came across are having to replace the entire front suspension and all four o2 sensors. I highly recommend that if you are to own one of these trucks especially the 2005 that you have advanced knowledge in mechanics, otherwise you might as well just give your paycheck the garage.
This will def get up and go on the highway. If you are driving for any elongated period of time your gas mileage with the v6 anyway will hit up near 20 to the gallon. the dash is great and the durability of the frame is very impressive. the set up is very truck like not a whole lot of trinkets and doodads. very basic and direct truck. good for hauling light loads and great for long trips...
Better seals in the transfer case. more space to remove the o2 sensors. grease fittings on the drive shaft. more torque for hills. better quality of material for the body. overall better quality of manufacturing