If one already has a decent down puffy is there any real good reason one should consider grabbing one of these jackets? I realize they are supposed to breath more, etc. but I would rarely (if ever) have an insulation layer of that nature on while actively hiking. The sale pricing makes it sorta tempting to check out but I have am OR 650fill Transcendent Sweater in green in the closet already so I'm thinking save my money here... (Men's Transcendent Sweater | Outdoor Research | Designed By Adventure | Outdoor Clothing & Gear). Anyone that owns one have thoughts?