Great idea, poor execution
I bought this and then went on a 28 day backpacking trip through SE Asia. I got it because I wanted to try a stainless water bottle, while maintaining the ability to sip from it. At first it worked well, but after the first week, the top began to leak if it was stored in a non-vertical manner. This is fine while hiking and traveling with it on a back pack, but set the bag down it will drip onto everything.