I recently purchased the 2003 Jeep Grand Cherokee equipped with a V8 engine. When we test-drove the car, my wife commented that it sounded like (not felt like) the car stayed in 2nd gear for a long time. We didn't think much of that comment until after we purchased the car. Subsequently, we realized that it was the sound of the motor when the tachometer got about 1500 RPM that was what we heard. This sound is very annoying, especially since it is almost constant around town. It's a whining, droning sound that can be unbearable in a tunnel. Nobody at the dealership acknowledged that there was any unusual noise. It wasn't unusual because it is usual in the Grand Cherokee, and from what I learned, in the Jeep Liberty also.
If I had my druthers, I'd return the car for that reason only.
Other than that, the car is powerful and well appointed. The heated seats with memory are great and dual heater/air conditioning controls are perfect for us. The car rides very nicely, although I can compare it only to our 1996 Ford Explorer.
I wouldn't be too sure of the mileage claims. After about 1100 miles, my message center says I'm getting about 13.5 mpg with 80% local driving and 20% long distance.
What I thought was interesting was that we needed to fit golf clubs from side to side in the rear storage area. The Jeep Grand Cherokee was one of only two mid-sized SUVs that permitted this. The 2003 Ford Explorer, although 5" wider overall than its predecessors, is actually 4" narrower in the storage area from side to side. Finally, we think that the Grand Cherokee is the best looking of the SUVs, and the silver color we chose, always looks good no matter how dirty the car.
So I'd advise a long test drive before purchasing the car. You really don't realize the noise problem immediately, until it has been pointed out to you and you pay attention to it.