Mine ICON PRO squeaks at times.....not sure what the deal is there, but I've heard the same complaint by others. I do like the ability to switch out bag sizes. But, I am going to try Stone Glacier on the next go around.
It's a bitch to get into, but for tree stand whitetail sits in cold weather, I use a Heater Body Suit. I get cold easy, but I can sit all day in that thing. It is like being home in a cozy, warm bed!!