Ok, well I installed the blacks on my non-revalved bilstiens on Sunday and have taken most of the week to really get a feel for them over a range of different road surfaces. I would have to say that the change is not drastic by any means. When the road surfaces are tough, for example there was a ton of construction in San Francisco when I went up there yesterday, you still feel like you are being tossed around and your car is being beaten (I feel like this is due to the shock valving, and less to do with the spring). On smoother roads with dips and smaller bumps, you can really feel that there is a bit more give in these springs and you dont get the strong "push" upwards which I always described as the "bounce".
As for ride height, I actually think these are a bit lower than the yellows, and maybe thats just because they are softer and just ride lower. Thinking about this when installing them, I did raise the rear circlip up one notch from middle to compensate, but it was so minute that you can barely tell.
I have noticed a "clunk" in the front end after installing these, but only when I hit speed bumps (which I drive over every day at work). Not sure what it is, as I have checked every bolt twice.
Overall, I do like these better than the yellows because they ARE a bit softer. That being said, I think the re-valve would also help reduce the jarring you get on rough surfaces. I still find that I can't really use my headrest in my car unless I am on smoother highways going highway speeds.