My Father in law owns a Grand Cherokee that must be just about out of warranty by now, his is basically just a blacktop run around, no offroad and no towing.
They are very nice to drive, very torquey diesel mated to a great transmission.
I did strongly consider buying one a few years ago as I needed something primarily to tow my 2700kg boat on the blacktop and they are cheap to buy and give a lot of bang for your back.
Here are the reasons I did not.
1. They are very small. A Pajero is much much bigger in the wagon compartment behind the second row. The space behind the 3RD row of my Y62 is not much smaller than the whole cargo space of the Jeep.
2. No matter how much I researched to find good stories on reliability and ease of service etc I still found a disproportionate number of reviews and accounts of total misery on the reliability front. I think its pretty fair to say that Jeeps carry a reputation for poor reliability and that reputation is more than hearsay.
3. IMO They do not age well. My father in laws JGC with only maybe 60,000km on the clock that has never been offroad, doesn't have kids kicking seats and making a mess in the back feels decidedly second hand inside. All the hard plastics and the chromed plastics, even the marking on the switch gear, start button and the plastic on the gear lever are all showing signs of wear which I would rate as totally unacceptable. My Nissan which is treated pretty poorly by my kids and has done more work looks brand new inside when I am motivated enough to give it a proper clean!!
4. Service costs.
My father in law and I both use the same independant mechanic. For the cost of the Jeeps genuine oil filter my mechanic can do a basic service on my Nissan using genuine Nissan filters and quality oil. He was miffed by the cost of Jeep parts!!
If you dont plan on going too far from civilisation, not looking to go off-road seriously and are happy to take the chance on something very expensive going bang and dont need much room to store stuff then sure go for the 2nd hand Jeep.
Personally I think the Pajero is a much smarter buy, my mate bought a relatively late model diesel Pajero with only 50k km on the clock for low 30's. We give that thing a pasting on paddocks chasing pigs, spotlighting etc and its a good solid unit that takes the abuse well.
Other options if your not opposed to petrol powered vehicles include the V6 Prado, I owned a 2003 4.8 Petrol powered auto Patrol. If you can stomach the 4.8's fuel bill you wont have to worry too much about reliabilitt, they are a rock solid unit.