I have a Grand Cherokee V8 4.7L with Quadradrive (2001). If you want power and power to pull like you are pulling nothing I recommend these. I have had no problems with it (my wife drives it and I drive it when home). All I have done is service it twice (£220 and £190 respectively, including plug change each time) over the past year (being cautious as I want to make sure there are no problems when I am away) and replaced the power steering pipe (from top of engine to bottom) as it was weaping a little - see the driveway on the photo.
It is an effortless cruiser, it goes like a rocket if you push on the loud pedal or is a fantastic cruiser on the motorway.
V8 power and torque is incredible, pulling away is like you are no even going above idle and its so quiet, the feel of power is also nice and reassuring. Easy to drive too as its auto.
The quadradrive is a fantastic system, it will drive on one wheel if it needs to. Being a Jeep, they are made for huge mileages - the states is big!
I went to Blackpool (well, near Blackpool) this past week and at 70 mph it was on 1500 rpm and I made it there using just over a quarter of a tank (from Worcester). Although, sometimes I was doing 60 as we wanted a lazy quiet cruise with no effort, and that's what I got.
It was extremely comfortable. I loved it actually.
Cheap enough (around £3000.00), mine has 68000 miles on it. At this price you can't go wrong. Of course it will eat fuel if you cane it, but, it has never bothered us.
Left field choice, but well worth it.... read some reviews!