I bought this bottle because it's stainless steel, relatively light and keeps temp of the contents pretty well. I used it for about 3 months, water only. It developed a really bad smell inside although I did clean it with soap and water, and a brush. The smell was so bad that I don't use it anymore. I emailed Guyot Designs to see what I could do but I never rec'd a response. Too bad.
This review was written in the old system and had content requirements that are different than reviews written today.