Re: Questions from a prospective buyer:
Depreciation- It is potentially more an issue with Jeep than some other brands, but it depends on how long you keep the vehicle. If you keep it five or six years, it's less an issue than if you swap it out after two.
Reliability- Yes, there's things that can go wrong, but generally the drivetrains in the Grand Cherokee are proven. The Hemi/545RFE combo is well proven and known to be good. The Pentastar/W5A580 is less so, but the transmission is a Mercedes model that has had the bugs worked out. The engine is new, but so far, it seems just fine. In fact, it seems like there's fewer issues than with the Hemi; the one documented failure we've seen on the board just didn't have a good cause established. While the owner denied it, it looked more like hydrolocking than premature failure due to defects and we just never got a straight answer.
The only real trouble spot we seem to be seeing is the Quadralift suspension, but that's no surprise; air suspensions are notoriously more complex than a standard metal spring. If it bothers you that much, get a Limited without QL or opt for an extended warranty.
There have been some quality control issues here and there, but by and large, the Grand Cherokee seems to be reliable in a "won't leave you stranded" sense.