The firmness of Mercedes seats has always been a deal-breaker for me. Only the S-class has proper seats and Mercedes should make those seats standard across the entire product line. Unfortunately, the S-class price has risen to stratospheric heights over the years. The only good thing about Mercedes seats is that the driver and front passenger get identical seat features and adjustments contrary to some manufacturers who provide proper adjustments only for the driver -- that's like giving you half a car in my book.