OIMO, First, the courtesy of a welcome to the forum. Blizzard Bags have been a UK product for several years and are now available worldwide, with a US distributor in Texas. I hope to test one in the near future. Anecdotaly my UK contacts are all favourable to it's carry and use. This includes winter climbers in Scotland and a member of the RNLI. I would be very carefull of ALL charts and graphs with formulae 'showing' X product performs at some %level vs product Z. The best of formulae, and some are GIGO, are at best approximations of the real world and at worse sales hype. Back to my collected, anecdotal, real world observations. The Blizzard Bag does require a bit of care to enjoy full performance. This translates into first trying one out at home and becoming familiar with the nuances of use, not in the first stage of hypotermia in the dark on the Pennines. It is EMERGENCY KIT, not a dedicated sleeping bag on the cheap. It's virtue is acceptable performance for the qualities of reduced wieght and bulk. For that it is a good product to stow in the Landy- and probably lets in less cold air.