I got this because my husband has tinnitus and has a hard time sleeping in the winter when we don't have fans on.  Otherwise, I wake up in the middle of the night freezing because he turned one on!
I love all of the sounds other than summer, only because I'm very sensitive to high pitch noises and the crickets hurt my ears.  Our favorites are brook and ocean!
I was surprised by the quality of the sound based on the size of the unit.  I thought for sure it would be tinny, but it's not.
I also love the small size since we travel a lot and it's easy to throw into our carry on bag!
We haven't needed to use the battery option yet, but it's nice knowing it's an option! [This review was collected as part of a promotion.]