I can't tell you how it works yet, because my home is still being constructed...but I'm going to use a Wattstopper DT-355. The 355 is specific for line voltage, the 305 is for low voltage. It's a duel technology (PIR/Ultrasonic) that will be used with two Liftmaster 8500's, as I did NOT want to use the factory bubble light.
That is a nice unit but expensive! I'm going to look into this more any other suggestions?