My buddy had one, swears by diesels. He is/was a jeep guy for a long time. He towed a little camper with it, definitely needed air bags and the brakes are way under par for 7k lbs. Its also too light to tow too much with. Cross winds really screwed with him towing the camper.
He was plagued by wiring gremlins and pesky coolants leaks ALL the time. He had a nice winch bumper on it and no lift, he averaged 23-25mpg. Best he ever saw was 28mpg and that was at OBX doing 45 at sea level. The torque is nice, they are fairly quiet for a diesel.
The front seats are TERRIBLE!!! I mean they suck so bad they could be considered torture devices.
They ride decent but his had so many little issues he couldnt justify keeping it. To tow often the trans needs upgrades as well. He ditched it for a TDI jetta and tows the camper with his wifes 4 runner.
This isnt a buddy of a buddy of a buddy, its a close friend and I drove, rode in and worked on his liberty a lot. My wife also owned a 04 gasser Liberty. She loved it but like most chrysler products it suffered from electrical issues, trans issues and premature rust. Look for rust in the rockers, under the flares and around the hatch. Specifically the pinch weld around the top of the hatch opening.