What are your thoughts on Bilstein B4 OE Replacement Strut, the black ones? Their description by tirerack sounds promising for OEM springs but wonder what real lie experience is the same:

"4 OE Replacement Strut are Original Equipment twin-tube, gas pressure replacement struts for drivers who want to restore their vehicle's original ride and handling.
Valved about 10% firmer than stock, B4 OE Replacement Strut feature the same German engineering and quality as Bilstein's monotube gas pressure shocks, but in a competitively priced, twin-tube design.
Not recommended for use with lowering springs. Limited lifetime warranty is included."

Attached Images

 

__________________
'05 E53 X5 4.4i, '97 E39 528, '07 E92 335i, '16 F86 X6M.