Millie Dayton wrote a review of Platypus Insulator Hydration System on October 21, 2012
Familiarity: I've put it through the wringer
Took this insulator on a recent trip up Kilimanjaro. Was advised that water bladders would freeze but it's my preferred method of drinking when hiking so I searched high and low for an insulator. This worked a charm. Filling was easy and the only slight freezing I had was summit day and even then it was only the mouthpiece which warmed up within 10 mins. Would totally recommend.