Last month I went to Colorado and had a 2012 Dodge Ram SLT Quad cab as my rental vehicle. It was a 4WD with the 4.7 V8 and 6.5 ft bed. I spent 5 days in this truck and drove it about 1000 miles in both the mountains and the flat lands. Overall, it was very comfortable and quiet on the road. In the flat lands, it got 22-23 MPG in straight highway driving. Powerwise, it pulled the mountains well the the cruise control would hold the correct speed both up and down hill on moderate hills. One thing i noticed was the engine braking was pretty week. I drove US 550 between Silverton CO and Ouray Co which has several hard pulls and steep grades. I've driven this road before and usually would downshift to 2nd and only have to use the brake minimally. Not in this truck. I had to put it in 1st gear and the engine was turning 4000 RPM and still gaining speed making me use the brakes more. I'm glad i didn't have a trailer pushing on me from behind!
I drove the truck off road and used 4WD twice for about 10 miles (don't tell the rental company). This was on a rocky road with a only a couple of steep grades. The truck performed very well in 4 wheel low and 4 high. However, I didn't drive in mud or anything really tough.
On the highway, the coil springs were very smooth- smoother than in a Chevy or Ford i drove recently.
The only other negative was the lack of power off the line. If i wanted to quickly accelerate into traffic, i really had to floor it to make it move out and then it wouldn't really start pulling hard until 4000 RPM. I was really surprised Dodge would have a truck that performed that way.
Overall, it was a nice comfortable truck that drove well. The gas mileage was great but if i were to buy one i would sacrifice a couple of MPG and get a HEMI. With a HEMI, it would have been sweet.