So far, I've had no reason to go beyond +1.5 turns front and +1.25 turns rear relative to full soft even for track days. I'm still on the OE springs. More than one instructor has commented that the car is composed at those settings (and with the rest of the setup).
With the wheel & tire upgrade (that hasn't seen track time yet), I expect I might increase those settings a little.
For the street, it depends. With my wife present and a lot of driving on rough pavement expected, about +3/8 and +1/8 turn. Alone, anywhere from +3/4 & +1/2 to +1 & +3/4.
Norm