I am pretty sure that Bilstien offers a sport shock as well, which would probably give you a nice compromise between the heavy duty and the comfort. As far as the lifetime warranty my car is on its original set at 180,000 miles and almost 15 years. Now, when they wear out I don't expect Mercedes will replace them for free (wouldn't that be nice). Generally when place give a lifetime warranty, it means just that, however long, as long as you own the car. We put a Walker Quiet flow muffler on the Caddy we used to own (it was stolen - notice I'm not crying about it)and the deal was as long as we owned the car it would be replaced everytime it wore out. So if we owned the car for 20 more years (not likely) we might have gotten 5 or 6 mufflers out of the deal. If you sell the car, I'm pretty sure they won't honor the warranty for the new owner. Its all a numbers game and it works like this. Unless you were dumb enough to buy a car without checking it out first it will probably be two to three years before you need these major items on a used car. Chances are 10 to 1 that if you have owned the used car for 2 to 3 years you will only own it for2 to 3 more years and then sell it or scrap it. So on average they only are looking at having to honor 10% of the warranties. Now with a Mercedes, chances are your original bilstiens lasted 10 years or more. So you buy a new set to replace the tired ones and they should last ten more years. Bilstien knows that the majority of people who buy shocks from them will not own the cars they are putting them on in 10 years, so they won't have to honor the warranty. If you do plan to own your car for a long time to come than this is great you may just get to take advantage of the lifetime warranty (and any short term problems - as mentioned above will also be taken care of). If you sell the car and the warranty was worthless to you then you still get more than your money's worth out of a set of bilstiens.
1995 E420 - retired
1986 420SEL - retired