I bought this one a couple of weeks ago as I really like my other diffuser from Saje. I've tried all three settings - 3 hours light on, 3 hours light off, 6 hours intermittent. All three work great and the auto shut off is exactly what I'm looking for. I've been using this in my bedroom and it's helped me with my sleep greatly. It does make a buzzing noise when the top is not closed off properly so make sure to close it properly. If you're looking for something quiet/silent, then this isn't the diffuser you're looking for. But if you don't mind a little bit of white noise (which I like while sleeping), it's great!