I got a chance to try this jacket, and take it on a long alpine hike with glissading and rock scrambling. I have never held a lighter piece of clothing in my life. Seriously, it's so light, you can see your clothes through it! But that doesn't mean it doesn't function as an awesome rain jacket (and a great sun jacket too!) Features: large hood, nice cinchy sleeves, two zipped up side pockets,
I wore it while hiking up a long snow hill and the ventilation in the pits (a bunch of tiny holes) worked great - I didn't feel the need to take it off with exterted effort. I was super glad to have it as sun and wind protection - it did a good job with both. No actual rain experience in it, but I threw some water on and it beaded beautifully.
The only downsides I would say are price (ultra-lightweight, waterproof and featured don't come cheap!) and the fragility of the fabric (definitely don't take this guy on your off-width climbing project!)