Front Suspension problems of the 2007 Mercedes Benz E550

Purchased car in August 2007, have driven 40,000 miles and have replaced 2 stock rims, 6 after-market rims and five relatively new tires due to just average potholes that any other car would simply roll over. Part of the problem is the low profile tires but there appears to be a deeper problem with the suspension. When this car hits a small pothole or even a deep manhole cover it takes a very hard, teeth jarring hit to the front end suspension. I also drive a competing brand 8-cylinder sedan which is very near to this mercedes in size and weight but hardly feel the bumps that pound the mercedes.