Thats an interesting way of looking at it and probably somewhat true to an extent. Realistically I think that a lot of people use S500's as daily drivers though. Then again a lot of Americans use Ford Expeditions as daily drivers too!

If you look at the entire Mercedes line from the beginning to current you will notice a trend. In the beginning most of the early cars were powered by 4 and 6cyl engines. In the 1970's when Mercedes started importing more cars into the US thats when the larger engines started showing up to compete with the domestic cars we have here which had large big block V8 powerplants. You will notice a similar trend with BMW's except BMW was a bit more aggressive with promoting their 6cyl's for weight balance.

In europe the 140 chassis is also offered as an S280 and even with the 2.8L 6 is quite powerful enough to move the car. I think Princess Di was killed in an S280 hotel car.

Anything 97 and on is ideal in a 140. Learn the shortcomings of the 140 and be proactive in its service and repair before the items fail and you will be much less fustrated. I read something about them resolving the headgasket issues in late 98 on the S320's but I have not confirmed that. The later model 98's and 99's have some slight differences on their 722.6 transmissions with the deletion of the drain plug on the torque converters for some cars. I have heard that some MB dealers have special flush machines that are designed only to flus 722.6 transmissions.