We purchased our F-250 Superduty Lariat 4x4 Crew Cab specifically to tow a travel trailer. Other than towing the trailer it is rarely driven. We specifically wanted the older 7.3 Powerstroke diesel as the newer 6.0 Powerstroke has had lots of reliability problems. Rumor has it Ford has hade to buy back thousands of 6.0 equipped trucks under the lemon law. Mid year 2003 is when the changeover was made from 7.3 to 6.0.
The one thing We did not know at the time was the short bed's fuel tank is smaller that on the long bed, 29 gallons versus 39. The 29 gallon tank is a bit small when towing a trailer and getting 12-13 MPG, and obviously the short bed box holds less stuff, in retrospect I wished I had bought a longbed. Superduty trucks are great traveling vehicles, are quiet and comfortable for driving long distances, very limo like inside with lots of room and great visibility. These things are as powerful as a locomotive. We crested the 10,000 foot Lizard Head Pass in Colorado at 65 MPH, trailer in tow, without breaking a sweat. Even though our truck has the "FX-4 Off Road" package, it does poorly off road. The original Firestone Steeltex tires readily dig into the ground and don't provide much traction. There is not much ground clearance either. I'm sure a lift kit and larger wheels & tires would greatly improve off road performance. Another minor irritant are the upgraded chrome tube style running boards. When driving in mud the front tires throw mud up and on top of the running boards where you will step in it and track mud into the truck when you get in and out. Build quality is about average for contemporary American built vehicles with lots of cheap low quality plastic parts that won't age well. The windshield glass is thin and has already cracked.

UPDATE- Feb 2008: Replaced the original Firestone tires with Michelin LTX M/S's, which made a noticable improvement in smoothness, quietness, and tracking down the road. The truck now has 60,000 miles on it and the only problem so far has been a crank position sensor replaced under warranty. Averaging 13 MPG towing, 17 MPG Not towing.