All concerns listed above are valid, but I believe that to some extent Mack is asking about the “family weaknesses” of this particular vehicle if somebody knows about them.
At some point I toyed with an idea of that generation Cherokee, so I made some prep-search on what to expect.
First and foremost, this is a Chrysler product, with all it entails 
Other than that, the 4.0-liter straight-6 engine there is very reliable and in 2001 model year it was actually relieved from the problem of cracking engine heads, so I would not expect much trouble from the engine, given it received due maintenance. I would never consider 3.7-liter equipped Jeep from the later years, as it was a real troublemaker.
From what I recall, transmission in 2001 Cherokee was also OK, no major problems if maintained properly.
Other than that, I will support all comments above: it is 18-years old car, so it will fail here and there and should not be considered for the primary/commute vehicle.