Transmissions- W126 1990 300se/1987 420sel/1991 560sel

[Two560Two]

I have noticed a difference in the shift points and smoothness of the transmission btwn the 90 300se(85k miles), 91 560sel(125k miles) and 87 420sel(57k miles). My 420sel shift much much much smoother and direct than my 91 560 and 90 300. To me, the 560 and 300 transmission shiftpoints feel the same and doesnt seem as smooth as my 420. Why is that? All cars are serviced well and no problems with them to date so an ill mileage difference should cause a difference?. Could it just be that they were made that way? Just though of posting a late night comment. Any feedback on this?? Thanks