This jacket is amazing so far. To be fair, I have only used this a handful of times in light to moderate rain, but it has kept me completely dry every time. I use this as a packable for running and bicycle commuting. It packs down to a soda can size, so takes up no space in a pack or vest. Was a toss up between this and the Outdoor Research Helium II for size, weight, and waterproofness. The mitts and vents made this an easy choice despite being $30-65 more depending on the sale. Jacket vents as well or better than any other I have worn and without annoying pit zips. Only thing I cannot comment on is durability. I am always fearful of gear that is this light and packable. But it gets five of five 'til it proves otherwise. For sizing, 5'10", 151, 39in. chest, 30 in. waist and I went medium. It is an athletic fit at best. Not much room for layers.