Well, I am currently running 285/65/18 on my stock XLT wheels. They are E-rated KO2s. The ride is harsh and stiff. Over the weekend I did a test fit with 17" Raptor wheels running the 315/70/17 D-rated KOs and the ride was much more compliant. Not like a tank with the E-rated.
Now, the additional sidewall probably helped as well, but the truck also felt faster with the bigger tires. I am pretty much set on going D-rated with my next set of tires as I like the feel of the truck better with them. That's just my opinion though and you know what they say about that.
I love the look and traction of the KO2s. They are great tires. Just not willing to suffer the E-rated ride again. Unfortunately, KO2s are all E-rated and I was hoping that the Raptor tires would again be D-rated.