I hope I can get the right balance with the Billies, as I understand the KW v3's and PSS9/10's are similar when set up correctly, or appropriately
I have also used Eibach coilovers, Koni struts and springs and a PSS9 kit on the same car (an E39 M5) and really liked the PSS9 as it was so adjustable, with some prior experience of setting up suspension (but not nearly enough !) It took some time to get a balance that I liked. My girlfriend did get a bit bored of lay-by's as they were usually an opportunity for me to get out, lean under the car and adjust.....
Having spoken to a few that do know what they are doing, I recognise the potential for me to get very lost with bump and rebound... 10 settings front and rear, easy adjustment with a kit I have used before persuaded me
I am very happy with a well damped thud and slight skipping over undulating surfaces, much less happy with 'crashing' over bumps. My last car was superb in this respect, an E90 M3 with nothing more than H&R springs. I fitted them quite quickly after purchase and never wanted to change after. I just moved from middle to full stiff depending how much I was pushing the car. The 'hard' setting felt a little skittish unless you were really loading it up. The 'comfort' was juts too soft for me, I don't want to drive a limo even in traffic.
I hope I can get a compromise to suit