IMHO if your looking thru forums before purchasing and you want a C300 Sport Package or C400 don't buy what's on the lot, order it instead. Dealers do not have any Airmatic's on the lot. At least from what posters have stated and my own research looking at some other states. There are two Dealers in Vegas and one dealer had a C400 with Airmatic and since it has been sold none since. Probably ordered by someone and they didn't want it for whatever reason. I have experienced and others on here with the salesmen trying to talk you out of it. Not sure why except they want to sell what's on the lot. Another poster stated that non Airmatic's is all that Mercedes is sending to Dealers. Apparently so. I made the mistake of not paying close enough attention to online reviews. If you notice most of the C300 Sport Package and C400 without Airmatic are reviewed in Washington state. They must have perfect roads and maybe I should move there to fix my issue Most of the rest of the C300 Sport and C400 reviews online reviewed elsewhere in the country come with Airmatic. Which suggest Mercedes is aware of the steel suspension on C300 Sport and C400 is way too harsh. I drove a Bimmer and you can have sporty suspension and enjoyable ride together. Maybe BMW has tuned their suspension better with Runflats and Mercedes hasn't gotten there yet. Either way you will notice the majority of Posters on here have ordered their car with Airmatic and you notice on some posts how glad they did. So let this be a consideration when shopping for your C300 Sport or C400. IMHO it would be best to order it. One last thing because of the harsh suspension there is a rattle in the dash that I am having fixed tomorrow. It started around 300-400 miles on car. So assume it won't be the last time I will need to go in for rattle fixes

 

All of the steel suspensions can feel harsh over rough pavement and breaks in the surface. I've felt this on both the luxury and base versions. The sport is stiffer than the base, but not dramatically so.

Have you test driven the base or luxury steel setup for comparison? The Airmatic is supposedly the most forgiving of all the suspension choices, but I'm not sure the ride characteristics of the steel suspensions are dramatically different from each other.