This reservoir is overall very good. I haven't had any problems with an off-taste. I have two minor gripes about this though: for starters, it isn't very easy to get the bladder out of the insulation sleeve. More like pain in the ... The second problem is that in very cold weather, the water will freeze in the mouthpiece, and you'll be trying to thaw and/or crunch a block of ice in your bite valve.

I was expecting this feature at the minimum, so I bought this brand to go assured. So far I have use it four times and used with only water on it and flavor gets continuously stained with some plastic flavor. I have kept it overnight with water on it and empty on the morning and filling it back before going out but still not good. I wonder if some more break-in is needed. Anyway may be this is a general problem on all bladders regardless the brand. Construction and materials is great and isolation keeps the frost away fine and there are no leaks and because in the end the main purpose is to keep you hydrated I still give it 4 stars.