Originally Posted by E46CT

Back in my track/canyon days, Bilsteins were the undisputed superior kingpin, even over the other "racer" brands which there'd be horror stories if blown seals and stuff.

Bilsten is the supplier for the 3IS F Sport stuff (and assuming 2IS F Sport stuff too). So you know it's the name to trust.

I once pulled a set of Bilstein B8s off a 97 M3 once w/ 215K miles, owner said he had them on the car since new... Caked on dirt from 14 years of use (at the time) yet so firm at 215k, was extremely hard to depress it with hand and a ton of body weight. Super hard still. Was super impressed. I got them super cheap and it was on a toy/beater car I was restoring on a budget but otherwise i'd buy new. installed them and they rode terrific. Debating sending them to Bilstein to get them rebuilt but decided to just roll them.

The Bilsteins (at least their heavy duty stuff) are just built with bigger shafts, monotube design etc so just inherently strong. not sure what they have for 2IS but for me if I ever have the choice, Bilstein absolutely hands down, particularly for longevity. I've done dozens of ground up suspension rebuilds and it's not fun after a few times. So get something you can install once and never think about it again.