I ordered the same springs, but I haven't recieved them yet.
Did you experience any head lamp leveling issues?
Have you had the car aligned since installation?
if so, are the front and rear camber results within the Lexus spec tolerance?
If you feel your lights are too low you can adjust them very easily. I did that on mine.
Why is the camber -0.7 on the driver's side but -2.1 on the passenger's side? I'd expect them to be much closer than that after the spring installation.
As for camber, negative camber up front will increase cornering grip (decrease understeer) but decrease straight line stability. Negative camber in the rear will increase cornering grip (increase understeer) but decrease straight line grip. I think the GS is a fairly neutral-handling car (for something of this weight class) so I wouldn't want to tweak the camber differences front to rear to too great an extent.