I already have the Hemi in my Unlimited Rubicon, as mentioned previously. I went AEV because of the lack of troublesome reports and mine has been 100% trouble free.
There is no shortage of power, but from time to time the weak Chrysler programming will have you thinking, "why the hell did (or didn't) the transmission shift up (or down)?" Its rare but it happens when accelerating on the highway. And that is with AEV's improved shifting already set up (but I might try the tow setting to see if AEV's Procal can improve shifting some more.)
To me, this LS set up is the perfect way to go with an X bought cheap - and maybe with the 0% financing Jeep is offering on the '11's, or maybe a well kept mall crawler from an earlier year. Use the savings and the free money to instal the 5.3 and go with a set of Dynatrac ProRock's, the .5" thickness HD 44 up front and the 60 (maybe the full float?) in the rear. Here's my math - 5.3+6l80 = $15k, Atlas = $2k. Thats $17k. Maybe another $6k for ready to bolt in axles with good shafts, ball joints, u-joints, thick, strong, HD housings, HD forged C's...
Then set the Jeep up with AEV's suspension and bumpers/tire carrier, armor and River Raider's aluminum skids with the ultra high density plastic stuff. Close to perfect... Another $3k gets you the 6.2, but that is just gravy, more than req'd to transform the JKU.
Actually, its a shame Chrysler doesn't offer a good smaller Hemi - not that I'm complaining about the power of the 5.7, but it really is more than enough.
Two other notes.
One: I get between 15 and 16mpg on the highway even with a small roof rack, and that's about as good as any similarly equipped 3.8 JKU riding on 37's, armored, loaded... Around town milage drops to an average of 12.8mpg, but that is no fault of the 5.7VVT, it just that there are more opportunities to run it. BTW, I am running oem Rubicon axles and oem DS's without any issues. I try to be smooth, the abundant torque makes that easier.
Two: I saw Richard Petty (I think) talking about the new Hemi Challenger on Speed TV the other day, he was saying that the new Hemis all have more HP and especially torque than the 426's he used to win Daytona.
JPK