The Grand Cherokee ZJ and WJ were each “upscale” with more accessories and even V-8 options. A 'Grand is slightly longer wheelbase and weighs more than an XJ Cherokee. This makes the base 4.0L inline six engine less attractive in the ZJ or WJ, as it works harder than in an XJ.
Through the WJ Grand Cherokee, the model has a uni-frame body and beam axles front and rear like the XJ Cherokee. The beam axles are a big plus for both longevity and service needs. Rear axles can be a Dana 30 or a 44 (aluminum center section) on the V-8 models.
If I were considering a Grand Cherokee, my preference is the 1999-2004 WJ model. That said, repairs and parts can be more expensive for the Grand Cherokee than an XJ Cherokee, and there’s typically more to go wrong at higher mileage.
A used, higher mileage Nissan Pathfinder could eat you out of house and home—very expensive parts and service, definitely a challenge to work on yourself…Compared to the fundamental design of an XJ Cherokee 4x4, a V-6 Pathfinder with high mileage would be more like a European car—something to avoid at high mileage.
The XJ Cherokee, it turns out, is the most utilitarian 4x4 SUV ever built—for functionality, reliability and from a maintenance or repair point of view...This is the "Volkswagen Beetle" (air-cooled era) myth come to life: The XJ Cherokee will actually run 250K-300K miles if maintained properly.
By contrast, an air-cooled Bug was lucky to see 100K miles without new cylinders, head and valve work plus lower end engine bearings—not to mention chronic replacement of chassis-length wire control cables, a Solex carburetor that would drop its discharge tube down the carb throat and take out valves and a piston, or the braided fuel hoses that baked under the rear deck until they split and spewed fuel onto a scorching hot, "fan cooled" engine with an oil cooler—and set the car on fire.
Need I say more? (I could describe the VW Type II bus and Type III hatchback and fastback frailties.) Better we should be happy that AMC/Jeep designed and produced the XJ Cherokee 4x4 compact SUV.