I've been waiting for that MSR Hyperflow filter to be released too, but I read that it is has a special kind of ceramic filter element that gets damaged if frozen...so it is really just a 3 season unit and would not be used it sub freezing temps. I hike a good bit in the winter time, and it does get into the 20s at times, so I may just go with the Katadyn Hiker Pro....at least that was the plan, but now I read this thread and am confused all over again.