A solid 10/10 for keeping fizzy drinks fizzy.  I have tried many water bottles and nothing comes close.  Also excellent at keeping drinks cold, although most quality water bottles will do this.  My two issues are about design.  This water bottle doesn't fit in my car cup holder, or in my bag side pocket.  Its too wide.  We aren't talking about 48oz or something crazy big.  The 24 oz bottles should fit into these pretty standard things.  I personally find the shape to be awkward and I would like to see a built-in straw.  Although i admit those last items are my personal preference.  I really wish this fit in my car holder, i would definitely order another.   That being said if you like fizzy drinks and don't like to be rushed drinking it, I recommend this water bottle.