I have the 25oz bottle, and have used it daily for almost two years. I fill it with seltzer from my Soda Stream, and it keeps it cold and bubbly all day. By now I figure I have saved hundreds of plastic bottles. My only complaint is that it falls over like a bowling pin with the slightest tap. I originally came to this website to see if S'well manufactured some type of rubber boot to put on the bottom to steady it, but I don't see one. Gonna have to fire up the 3D printer.