While the 4.0 l i6 is not the most powerful or fuel efficient engine it is truly bullet proof. I bought my grand Cherokee in 1998 and it had 60,000 mi on it. It now has 262,000 mi on it and the engine still runs strong. I beat the crap out of this car taking it off road. I sank it in a swamp, blew the shocks rock crawling, and various other adventures. The engine hung in there. The exhaust rusted because of the swamping and needed to be replaced and the transmission was replaced when I sank it in the swamp. But the only parts I ever replaced were ones that werew broken from my harsh useage.
Reliability... this vehicle never left me stranded.
drain plugs. when the interior gets swamped it takes hours to get the water out with a shop vac because there are no drain plugs.