Basically its mechanically identicle to the WK Grand Cherokee. It was pretty popular its first year but I think gas prices and its largely useless 3rd row killed it. Its not a bad truck, and I love the styling, but aftermarket support is pretty limited and since its dead, wont get any better.
The suspension isnt bad, if a tad soft, and is IFS so lifts will be limited. Quadra drive II equiped models (hemi limiteds and Overlands) is pretty advanced with front and rear LSDs and drivetrain parts are easy to come by due to being shared with the WK.
There are a few issues that imo limit its desireability for an expo rig. Fuel economy is terrible with any engine (3.7 V6, 4.7 V8, and 5.7 V8 were all offered). The rig is pretty large but interior space isnt any better than the Grand Cherokee due to the stepped design of the 3rd row. Seats up there is almost no space, down the load floor is very high and still not very impressive. Limited aftermarket support. The gun slit styling of the windows limits visibility quite a bit, though the limited models with 3 moon roofs keeps it feeling light and airy in the cabin.
All in all not a bad choice, but probably not the best either. That being said they are cool, especially with a mild lift and residual values are terrible so you can pick up a loaded, low miles example for under 20k and thats pretty appealing.
Hope that helps. Ive always liked these rigs.
Ive heard Jeep will be returning to the 3 row arena soon with a Wagoneer, or a Dodge Durango with Jeep styling and the Grands 4wd system...might even get the upcoming diesel.