I was on the same boat man. Except I sold my RS4 for the M5. You are a happy camper so that is all that matters! Enjoy the Panny GTS, its a hell of a car.
Current: AW/SO F10 M5 H&R Springs, 12mm/10mm Spacers
Sold:Imola Yellow RS4-KW V3, MTM 10mm spacers, Hotchkis rear sway bar, APR Stage 1, Milltek Catless, RNS-E, Euro RS4 Flat bottom Steering Wheel