First off... Nobody drives an X for the mileage. Your numbers are pretty close. That's what I got with my '04 Non SC before I started modifying.The Grand Cherokee will have more room, but size and the V8 will likely give it less fuel mileage.

Check all the usual stuff... oil, tranny fluid, brake noise, suspension slop & noise. Listen for an unusual S/C whine or growl. It may be wise to take a code scanner with you. Certain codes will put it into S/C bypass mode. Make sure that at that mileage (117K) that the timing belt has been done... and done correctly.

If you plan on wheeling, the X is far more capable. Also it's easier to manage on tight trails. Remember the "Grand Cherokee" was more street oriented.

Good luck!

Jeff!