I ride a scooter year 'round, and on cold winter mornings I'm looking for ways to make my (short) commute bearable, especially given my strong dislike of getting really chilled, even for a short period of time. I've noticed that if my neck and chest are comfortable, it makes a big difference. I've had lots of polartec-type vests and under-jackets, and decided it was time to try something a little more aggressive.Well, this is it. The way this lightweight garment cuts wind and keeps me warm is amazing. Solid problem-solving design.There are a lot of reviews that talk about the sizes running large. Here's the way I would address that concern: if you see this as being worn on top of a couple of layers, it will likely fit the way you expect. If you imagine it as a snug layer right over a t-shirt, you'll probably want to order a size lower than your normal size. I ordered my regular size, knowing that I would sometimes want to wear both a shirt and a sweatshirt underneath. It's comfortable and doesn't restrict movement even when used as an outer layer.Fantastic colour, fabulous quality awesome warmth- if I only was the right size. It strikes me as hilarious that almost everything in the Columbia range is too small until you find one that you think is gonna be the right size and it turns out to be so big. Will not be returning however has had to buy through a U.S.-based clearance House and returns are impossible (nice little twist thank you Amazon) plus the price I got this at- it's just not worth returning -I will make somebody very happy when I gift this next winterSize was somewhat large. I got medium size. It fit medium person w belly (dad) or large size person w less belly (hubby). Was fitting both very well. If you want to put some layers underneath, it will be fine, but if you are planning on putting short sleeve tshirt, it can be too big. It worked for me for my dad. Very good indoor extra layer for spring/fall!!keeps you VERY warm.Updated jan 2021: Just returned from ANOTHER ski trip and it kept me warm again have had it for 6 years with heavy use in the begining now more for skiing only. one pocket has zipper issues but overall love the vest.Bought this for my husband for XMAS. It came exactly when I needed it. It fits very well and he likes it a lot. Wore it everyday for a a week. Now back at work wears it on weekends.Ran larger than I thought so returned and purchased next size down. Didn't have this color so had to order different color but did cost me 30+ more dollars. That being said quality is great!I first ordered a Large size, since I am a medium build 6'3" male. It was larger than expected. Amazon's free return policy was the deal saver, and two days later I got the Medium size which fit perfectly. I don't use thick sweaters or much layering, so the Medium gives me a slim fit look, just what I wanted. If you're into thick sweaters or too much layering, then you'll need the Large.The medium I bought was true to size. Be warned though, because of the reflective coating on the inside the color is silver. If a silver liner is not your thing, you may want to look elsewhere.