Some more data points while waiting for installation. As always, expert opinions and corrections appreciated. BTW, how a car's suspension should feel is highly subjective in nature; if you think the Turbo is perfect as is, please skip this entire thread.

I called Bilstein re. ride height for PSS10 as there is a potential problem with hitting the damper's internal bump stop if you lower the car too much. The official recommendation is that ride heights be reduced 10-30 mm front, and 5-25mm rear. It's interesting that they do NOT recommend stock ride heights. That is, if you are using PSS10, you should lower the car at least 10mm.

You also might recall I was trying to decide between lowering springs and PSS10. A couple reasons that cause me to choose PSS10 (whether it's the correct decision I will never know, and it doesn't look like an extended AB comparison test drive will be coming any time soon):

1. AFAIK both the stock springs and the lowering springs I considered are progressive, not linear. Meaning initial response is soft, then stiffens with more compression. This setup is great for a street car, but may not be so for a performance oriented car. The PSS10 uses a stacked springs setup (each coilover has a main linear spring plus a tender/helper spring), which I hope will reduce the wallowing that the car does.

2. The damper in PSS10 is a monotube design, versus twin-tube for the stock. For some basic reading material: http://www.sportcompactcarweb.com/tech/0607_sccp_making_it_stick_part_6/index.html . Besides being technically better, I also think changing the damper of the stock system is a good start. Personally, I always feel there is something not quite right with the FIRM setting of stock PASM. It causes the car to feel jittery and choppy. (Take this with a grain of salt as I am the odd one who remains highly skeptical of Porsche's PASM as currently implemented. I think a single dampening rate that matches the spring is the best solution.)

I will find out in a couple days whether my amateur web research has guided me correctly.