I have Eibach springs and I'd guess that the car lowered by about 1" in the front and 1.25" in the rear (had to re-adjust the headlights as they were lighting up the Moon)
IMHO this is borderline in affecting day-to-day driveability as every driveway and speed bump now posts a challenge to me.
But then again the car looks much nicer and handles much better on the track
And my front left tire rubs a little when I have complete steering lock