I had an XJ before. Sold it. Missed it. Ordered a 2013 JK with the 23R option set and not much else, lifted it a bit, threw some 33s on it. It's a damn Cadillac!
In the old Jeep I got a used one with low miles, I lifted it, had it regeared, made the mistake of throwing a lunchbox out back, swapped over Ford Exploder rear disk brakes. It was good, but never quite "right". Should have just purchased a used TJ and built that out.
Anyway, buying new is really nice. I think it makes people a little more cautious and think through mods a little more. Maybe. Maybe not. Just my thoughts on the subject.
The new 3.6 is nice, noticeably different than the 4.0 I had. Better in many ways for every-day use and whatnot. With the minimal amount of time I've had to offroad it, the Rubicon crawl ratio is just sick. So, I don't feel like I'm missing any torque from the difference in power bands between the two. (Subjective, but that's what I observed)