A couple of points. Bilsteins are not necessarily stiffer, but replacing worn out struts will give the feeling of "stiffer", they do provide a great deal more wheel control - so I have them. The old bounce test is just not an adequate test for today's vehicles. If a car fails the bounce test it is definitely in need of work, but even if it passes (very subjective) it could still have seriously worn struts. My car needed new front struts at 85,000 miles which I sensed more from the feel of the car than a bounce test. Something to look very hard at is the top spring/strut mount which can fail. The center metal collar can separate from the rubber and cause the top of the strut to move around causing a lot of rattle-type noises. Push down on the front corner of the car and watch the top of the strut in the engine compartment. It normally move a little but if you look hard you can see if the metal collar is moving independent of the rubber spring mount. It took me ages to track it down because the noise sounded more like a loose metal item under the car, but that's a problem I had. Also look at lower ball joints which don't show their wear with the old "shake the wheel" test. You have to jack it up and use a large pry-bar to check the amount of free play. Bottom-line on the Bilsteins - I believe they are superior for control and don't make the ride worse.