I have recently changed my 4 litre Grand Cherokee for an ML. The Jeep is, to be fair, an excellent towcar. Very stable, more than powerful enough, and supremely comfortable.
Downside is as Bazza says, the auto kicks down to 3rd when the car easily has the power to maintain O/D.
Most of the negative stuff you've heard is probably true. The electronics in the Jeeps seem to have a mind of their own. The rear slipper diffs tend to slip less and less until the crown wheel strips the teeth from the pinion wheel. Gearbox torque converters tend to drain during long spells in O/D then rattle like a bag of nails at kickdown. And I've had one throw a piston through the block for no other reason than being badly cast.
Every car can have its problems but there is a saying in America that "(whatever the subject matter) is almost as unreliable as a Jeep".
Having said that, I loved mine. Would I have another?
No.