I think someone already posted this but in terms of other SUV's in the same category and class - the Jeep is bean pole thin. I have owned 7 Jeeps over the last 20 years - just got rid of my 06 SRT8 2 years ago - looking to get a 2012 (if , when, blah blah).
I did purchase a 2010 Land Rover LR4 - sweet ride but you want to talk about heft? I was crawling around underneath and it is like a sherman tank under there. There are these two huge pendulum looking things in the rear that swing back and forth with the vehicle (they look like 25lb plates) There is a 5 foot long 3 feet around air tank that goes down the passenger side on top of so much steel and other things - lots of stuff.
I also have an 01 Land Rover Discovery - same deal - its a tank. Land Rover's are the first vehicle I have owned that if you let them sit over a long weekend - the tires get flat spotted, every time and they need to work themselves back into round a few miles down the road.
All Jeeps are beyond lightweight when compared with these other classes - the ZJ, WJ and WK all flew with a V8. The SRT8 was beyond lightweight - hence great performance and handling.
My 10 LR4 has the new Jag motor at about 400hp/400tq give or take - the performance is good - but it will never be on par with the Jeep in terms of all out raw acceleration. Plus there is less drama - its butter smooth and dead quiet.
Anyway just a comparison.
PS - the new Jeep SRT8 is coming, just be patient.