I liked the look of the clad 20s on my '05, but not the tire selection. My truck is a tow rig for my rock crawlers, as well as a daily driver, and I just didn't feel confident on what amounted to a passenger car rated tire on the truck. Between the trailer and stuff in the bed, I was really pushing the limit of the weight rating on the tires.
While I didn't exactly scour the earth looking for load range D or E tires in a 20" tire, I did find them hard to come by. I wanted something with a decent availablitiy in case I was on the road hundreds of miles away from home and had a problem.
So I swapped for 17" wheels, wrapped in 285/70/17 Load Range E BFG AT KO tires. Yeah, I know E range is WAY overkill, but I got a rocking deal on them that I couldn't say no to