Love this mobile and am still using it with my almost 2 year old. My son loves the stars and moon projection on the ceiling and the sounds lull him to sleep. The timer is clutch. I turn it on at bed time and it shuts itself off after I've left the room and my son is fast asleep. There is a nature setting and a singing setting. My son did not care for the voice that sings, so we leave it on the nature/whale setting. I use that in conjunction with the Graco sound machine and it works together well, drowning out noise outside or downstairs.
I also love the feature that this will start playing (if left in the ON position) if your child cries or makes a noise throughout the night. It recognizes the child might be waking, starts playing and provides a buffer to try and lull them back to sleep before you would have to go back in. This worked out great as my son "sleep cries" a lot. It adds that little extra comfort and helps him maintain sleep.