I highly recommend it too. No leak, very well insulated.
I am going to throw in my vote for the Hydroflask as well. Someone gave me one as a gift a few years ago, and I use it daily. It keeps water cold no matter what the outside temp is, and I often have lemons or limes in mine for flavor, and the flavor never lingers once it gets rinsed out.
It is a little heavy if you're taking it on a long hike, but it's so worth it for the cold water and the indestructibility of the bottle. I've never had mine leak either.