I needed to replace an old jacket and I stumbled upon this Wanaka jacket at a local store. It was on sale but I was bummed they only had a medium. I usually wear a large in most coats and sweaters. I think I even have a size large Patagonia fleece jacket. But when I tried it on it was perfect. I'm 6'0" 160 lbs. I have long arms and these are just fine. I can't imagine wearing a large in this jacket, but I didn't have one to compare to. I use on early morning boat rides where it is often 20 - 40 degrees F at the dock and with the wind chill of the open boat at 35 mph it can be a bit chilly. With the zip up neck and the wind flap and the shell material and the quilted down interior, it is nice and warm. I am stoked to have found this jacket and it looks like it is built to last a long time.