Life of Shocks on W210 Car

[okc329]

I was wondering if anybody can provide information about the life of shocks on this car ('97 E320). I know it is probably affected by type of roads traveled and perhaps driving style. My car is coming up on 60K miles and it seems that on previous shock-equipped cars, I replaced them with fewer miles. Any suggestion about OEM vs good aftermarket types? Is there a simple test that can be done to determine their condition. I remember the old "push down on the corner and see how many oscillations you get" test. Is that valid here? Thanks.