I have owned everything from The North Face to Mammut bibs, and these are by far the best all around bibs I have ever come across. They are very light weight, extremely durable, and pre-fitted to the natural curve of the leg, whether youre skiing down a chute, or placing your crampon on steep ice. My favorite feature is the side zips on the legs...perfect for ventilation, or accessing gear. These bibs reflect perfectly what Arc'teryx is all about. I looked at the Alphas also, but I think these bibs breathe better (soft shell above waist) and are more durable with only 2 extra oz.