DIY'd the HD Bilsteins ... rides a bit firmer, but not a lot. Would never go back. Perhaps the differences in experiences on the HDs is related to the weight of the car. While the engineering design should take all this into account, I have a feeling size does matter.
The R&R was a piece of cake on these .... very simple to do a wheel at a time. Total time for all four using simple car jack and stands was about 3 hours.
1991 350 SDL (200K and she ain't bent, yet)
former 2002 E320 4Matic Wagon - good car
former 1985 300 CD - great car
former 1981 300 TD - good car
former 1972 280 SEL - not so good car
a couple of those diesel Rabbits ...40-45 mpg