This past winter I purchased the original version of his humidifier and used it all winter long. I recommended it to many people. It was smaller than I realized so the one complaint I had was the water tank size. When I saw they launched a larger version I ordered it immediately and tried it. This larger version lasts me 3-4 nights. It's basically a larger version of the original with several new features.  The tank simply lifts up and can be quickly filled up. I am a fan of this company and have purchased several other items from them and they never let me down! I highly recommend both the small and large version!