no direct experience w/this product but we got ds (bad sleep issues) one of the light therapy units that slowly lowers the light and then acts as an alarm clock in the morning by mimicking the sun rising and over preset time intervals would emit sounds (gradually getting louder at each interval as the light got brighter). it worked pretty well for him.
my only concern w/anything that employs a metronome is based on personal experience-in my youth i worked in a music store and one of my jobs was to test the metronomes when a shipment came in. i had to wind each one up and let it play itself until it needed to be rewinded-it never made me sleepy but gave me terrible headaches.