I'm doing my research into purchasing the right sleeping bag for summer alpine/uk mountain use. I want something which is waterproof and relatively lightweight which I can bivi in. The 2 bags in the subject header seem ideal and I was wondering if anyone has any experiences of using them. The Crux Torpedo 500 also seems to have increased in price from around £330 to £600 over a 4 year time period; which seems unbelievable. That said I can get the Crux bag on discount which would mean that price wise both bags would cost around the £300+ price range. If anyone has used these bags let me know what you think.