As a general rule, if you lower a car by shortening the springs....the spring rate must be higher, therefore a harsher ride. Look at it this way, you have only so much suspension travel available. If you shorten the spring 1 inch, you have to have a stronger spring to keep from bottoming out the suspension (and that is not a good thing). A rougher ride is inevitable.

Now the benifit of a higher spring rate is generally less body lean, once again due to the stronger spring. The downside is that if only one end of the car is modified, you have upset the handling geometry and the end with the stiffest sprint generally is the end that slides first.

For a vehicle like an ML, the reduction in body roll is insignificant unless the vehicle is pushed to it's handling limits on a routine basis. Basically, if you are not sliding the car sideways on dry pavement, you have gained nothing by changing the suspension.

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Litton
'90 420 SEL (sold)
'72 280 SEL 4.5
'98 ML320 (for sale)
'86 560SL
'05 Jeep Grand Cherokee Ltd (offroad in style)
'87 Chevy Blazer (AZ Pin Strips)