The best BMW seats in my opinion are the ones that have the 4-way lumbar adjustment and the 2-way upper articulating back. Which means the 16-way comfort seats or the 18-way sport comfort seats found in the e38.
If I can't have either of the comfort seats, then give me the basic e53 8-way seat & add the 4-way lumbar option for a nice 12-way seat. Or the e39/e39 basic 10-way seat with the optional 4-way lumbar option for a nice 14-way seat (the e38/e39 electric seats all have power headrests).
The 10-way & 12-way sport seats in the e53 & e39 may look aesthetically better and the 2-way thigh extension may be nice for those with long legs...but they just don't get all the individual body build adjustments that the seats with lumbar and articulating upper back give.
But sometimes too many options can screw people up if they just start pressing the seat buttons without a plan of attack. My BMWs with comfort seats & lumbar option...I always start out with flat affect...then adjust the seat buttom first...adjusting the height, tilt, and how far back fro the steering wheel (slight bend in elbows but arms not fully extended which can cause fatigue). I then move to the seat back & adjust the seat back angle. From there I adjust the lumbar....moving it up until it fits the curvature of my spine....then adjust the lumbar inward or outward...again based on the curveture of my spine.
If you have the comfort or sport comfort seats with the upper articulating back...then you can fine tune the seat even more to adjust to your upper back shoulder area and tilt it fore or aft depending on your posture and curve of your upper spine. The only way to not be comfortsble in these seats is to get confused by all the adjustability and not set the seat correctly to your body/posture/spine/height/girth.
Again, the 10-way or 12-way sport seats look nice...but if they don't have the lumbar support...it doesn't put them in the column for "most comfortable" seats. I always wished the 12 way sport seats in my e39 540iT at least had the lumbar option...I didn't find them uncomfortable...but could have been more comfortable with lumbar. Im glad my e53's basic seats have the lumbar option...at least my lower back gets some support...and the heated seat pad for the "lower back" area is nice, too.
