Seems like a general consensus is that you need lumbar and bolster for optimum comfort. It's funny how some features that seem like they should be standard equipment are still options on a 70K car. My 1990 735i had adjustable lumbar but my 2003 M3 doesn't. I do understand that they are two totally different cars with different purposes. One is for luxury and the other for speed, but there should be some adoptions of features which become standard equipment after a while (like air conditioning etc). However BMW seems slow to transfer options to standard equipment. I guess it's kinda like navigation which is still not standard equipment even on new M3s.
2003.5 M3 Coupe. Jet Black/Black Nappa/Full CF Trim
Eisenmann Race 83MM Bilstein PSS10 Michelin PSS