After lowering, I've had to raise my bi-xenon lights quite a bit. Something like 4 full turns on the adjustment screw to get it correct.
And, not a GSW, but here's my Golf on VWR springs w/ Bilstein B8s. Too low for me, and the ride is just a bit too stiff for daily driving so I'm going to try out the H & Rs in hopes that the slightly added travel gives a bit more comfort. The car is ultra responsive though, just too much for daily driving.