I finally put on Koni FSDs on my 2001 S60 T5. I'm not crazy about Koni only having inserts on the front, so you have to cut open the old strut and bolt the insert in. So far car seems to ride a bit higher (I didin't measure ride height yet) and the ride doesn't seem any more smooth than when I've had Bilsteins on other cars (a bit more jiggly than stock). However, response to sharp irregularities in the road is less jarring than with Bilsteins. Hopefully those bolts will hold the insert in over the life of the car - they're held in place with threadlocker and a lockwasher. Now to work up the guts to drill holes in the trunk to put on a spoiler.