My coworker's cousin has a JK Unlimited Rubicon and he let me drive it last night. I can't say I was disappointed, although it was way too nice inside for my taste. It has an auto tranny, he said he ordered a six speed first, but it was too anemic so he sent it back. With the auto, it seemed to have plenty of get-up-n-go. The 17" rims are absurd, luckily he's lifting it and throwing 35"s on
15" rims on it. Apparently, he can fit the 35s with only 3" of lift. He said 37s would fit with a 4" lift. I don't know what kind of suspension travel that allows or what kind of rubbing that would do with full stuff, though. I imagine it requires some fender hacking, too. I can't imagine putting 37s on with everything else being stock, but I think it's pretty cool that it's possible.