Yes, the "PWR" button is as the same minus the variable shock function of the skyhook cars. As to your second question, I haven't seen any factual or hard number data that supports extended clutch life by keeping the car in sport/pwr mode. Empirically though, most everyone likes the crispness of the shifts in the sportier mode and other observations have determined that reverse (especially up an incline) and "auto" mode are the hardest scenarios on the clutch.