DoubleA4

So I am looking at making the change to a lowered suspension and with it, making the upgrade (?) to SPC adjustable upper control arms. My general understanding at first was that they would be necessary due to the lowering of the car which would alter the suspension geometry. But after doing a little research I see that caster can significantly alter steering response and stability (its one or the other?). Anyway, so my question is, does changing the caster in either direction make noticeable changes to the steering response? Anyone else install these and can give some feedback? Thanks,