I upgraded my '12 X (18x8 - 265/60 18) with SRT reps in 20x9 and went with Hankook 295/45 20 for tires. My biggest questions were would they be too wide and more importantly would it really work on a 20x9 wheel. I was back and forth on this, but ended up going with the 295s as they were closest to original tire size in order to keep the speedo close.
I love the look, but my first thought was, "Oh man, I went to wide." I have been told rubbing was not an issue and so far I have yet to see any problems. They are growing on my though and friends all say they really like the look.
Overall I am happy with it, but there has been a learning curve when it comes to driving with this much rubber on the ground. For example, I picked it up and while on the highway there was a distinct pull to the left that I noticed. Thought it was an alignment issue so took it back, but was told the tires will follow the road a lot more now and with older highways having more of a crown I would notice it. I wanted to call BS, but on side roads there was no pull. I then drove in the right lane on the same stretch of highway and it pulled a little to the right. Hmmm. In the past few days this stretch of highway has been repaved and the crown is much less and I don't see the pull anymore. I also feel a little vibration in the wheel and seat around 70mph from time to time, but this is hit or miss.
In any case the Jeep is a lot more planted now. Tighter feel in the steering wheel too which I like. When cruising at 75mph I would feel the Jeep float some around turns and always ended up slowing down. I can now complete these same turns without having to tap the brake.
Here's to a fun Summer.