I had the smaller version of this but wanted something that would run for longer. I spoke with an employee on the store prior to returning and I was told there wouldn't be an issue exchanging the product. I chose this diffuser in stone and I love it! I like that it has the option to run for 1, 3 6, or 11-22 hours depending on what setting you choose. I also like that I can set how intense the mist is. I have only one of these but it works well for the entire ground floor of my house. I also appreciate that the automatic shut off feature. The only thing I would like to see changed in the future is the addition of the multi-colour light feature for the Stone model, as this feature is currently only available on the Black or White models. The information manual does not distinguish between the three colours thus I thought I had that option with my stone model, but I do not - not a big deal at all though.