I'm with you on the large rims. I found the 18" made the truck feel more harsh than necessary. Although, the 2006-10 Explorers are much more stiff with all the cross bracing in the frame, so I'm sure that contributes to the feel. But when driving over washboard surfaces it felt like the massage function of a hotel room bed! I can still feel it in the Tahoe, but not so harshly. I am considering getting another set of 16" rims for my all seasons and selling the 18" rims. These are the 18" rims with the plastic onlay that isn't replaceable if you crack it on a curb. However, I still have a few seasons of wear left on my 18" all seasons, so that won't be for a few years.
Next job to do: I discovered that the rear stabilizer links completely disintegrated, so they need replacing.