I currently own two super duties, one deisel and one V10, the deisel has 360,000 miles and is still running strong with minimal problems for it's age. The V10 has 75,000 miles and has had a few sensor problems but has been a great truck since day one. I just towed my 34' 5th wheel 600 miles with the V10 and it felt like I was driving a comfy car the whole time.
The V10 never struggles and can pull just about any hill without loosing to much speed, the only downfall is that it passes averything but a gas station. I averaged about 5 mpg towing.