Met all my expectations
I've been using another ZAQ diffuser in the shape of a disc and enjoying it for approx. 2 yrs.; so, I thought it was time for a change, and I must say, I didn't realize that THIS model in the pyramid shape makes such a HUGE difference visually and psychologically, (to me, anyway). I highly recommend this shape and size for a small room or living area.
I find that both my ZAQs are very efficient; and, from the reviews I've read so far, the ZAQ brand mfgrs. the best machine on the market.