I had mine replaced on the 560 SEL a few months ago at 100K miles. The car rode like a truck -- nearly teeth jarring if you sat in the back.
The hydro-pneumatic suspension was bled and deemed to be in good working order as well. I never suspected anything was up with that, as the car "sat" well etc. It was all in the shocks, pricey at that. Get them from here if you can.