I have had the product for a few years and did week+ hikes with it. You want to carry water weight and not a heavy bottle. Does not corrode, is robust and the right size for the backpack. I think I had over tighten an early version of the flask which prevented me from adding carbonated drinks. The response time from Vargo was amazing (seconds) and a few days later I had a new lid. A great product and amazing service. Now I will get the new bottle with the titanium lid. My wife will love it..at least I am excited for her.