bavauto is known for having a ride very close to stock but they do tend to sag quickly i guess. were they used when you bought them? also read the write up on bmwe34.net about springs and shocks.
There is a long held myth about so called lowering shocks or shocks designed for lowering springs with reduced travel versus shocks designed for standard or taller springs. The best way to visualize it without physically looking at the shocks side by side is...the only tangible difference is the stroke is shorter in a shock designed expressly for a lowering spring...the throw is shorter. Full jounce position or fully compressed shock position is exactly the same...that is the critical factor for bottoming...wh ere the jounce bumper fully compresses onto the top of the strut collar nut threaded onto the strut housing...that shoulder position is the same for either shock and each shock will identically compress into its cartridge casing. With a standard Boge shock lets say..the throw of the rod internal to the shock is a bit longer..that's all...so the shock is cabable of "extending" farther...at full suspension rebound or when the suspension arms are fully down with a taller spring. With a shorter spring..you don't need a longer throw shock...however..this is the important part...Is putting a standard Boge with longer travel with a lowering spring bad? Absolutely not...you just end up not using the full travel capability of standard shock with a shorter lowering spring... that's all. All the speculation of a standard shock..say Boge..wearing out faster with a lowering spring...is a myth. (From George Mann)
here's a link