While the insulation is certainly superior to that of a run of the mill blender bottle, and I was obviously not expecting it to perform as well as my Yeti or Camelbak tumblers, I did expect ice to make it a bit longer. It also does sweat, though again, not as badly as a blender bottle full of ice. I would estimate that ice chips completely melt within 1 to 1.5 hours in a normal temperature indoor environment without direct sunlight. The residual beverage is still cold, but if you like your beverages very cold, you would need to top off ice every couple of hours. Also, when walking briskly from my car to work with my mostly but not entirely full tumbler, some of the contents do spill out of the top, but not enough to create a mess or enough to spill on me. Would be nice if there was a rubber seal around the top where the straw is inserted like on the Camelbak. I'm overall pleased with my purchase though and think it's a good value.
Rating: [4 of 5 Stars!]