Do it. I bought mine from NH-Tuning.de
They feel surprisingly more compliant and smoother than the m-sport crap. Better control of the body. Ride height is perhaps 10mm lower in the front, on max height.
I would def. do M3 arms front/rear and whiteline subframe inserts($100, do it!) asap.
As you would know, they are the same kit as PSS9 but without the dodgey adjusters. PSS10 have the revised adjusters, although I couldn't justify the additional expense on a street car.
A few of us on here run them:
http://facebook.com/groups/130iOwners/