I am not a mountaineer or extreme outdoor enthusiast, however I admit to having a slight obsession with technical gear such as this. I have purchased around ten Montane Jackets / Shells over the past few years and found each to have more positives than negatives, particularly unlucky with zips not lasting much past three years? Anyway, this Jacket is by far the best product of them all - it is actually quite remarkable. On first inspection of the Jacket, I was sceptical (to say the least) around its insulation properties as this is one thin, lightweight Jacket. I decided to give it a real test on first outing and headed into the Cotswold Hills in torrential rain and wind that made your face sting within minutes. I am 6 foot 2 and 17 stone so Opted for the XL size and its generous, even with underlayering and particularly love the long sleeves that help insulate hands - even with arms like an Orangutan. Three hours of rain and completely bone dry, despite low temperatures I found I had to unzip briefly to allow trapped heat out as this thing is like an electric blanket even with low to moderate exercise - no problems with sweat as this is dealt with by the design. Only slightly negative comment would be that I would of liked a slightly longer hood. Windproof and waterproof - all day long. As warm as my old Montane antifreeze I swear, but with the ability to stay out in the extreme wet. Wouldn't hesitate to recommend - over a year old now and still like new