Like other Arc garments, it's well made, handsome, and probably functions extremely well. But it's much too roomy for me. At 5-10 and less than 140, I have trouble finding many Smalls that will fit properly. Unfortunately, this is one of those. I wish Arc made its Smalls a little smaller; then again, I'd need another closet if they did. Although this seems intended for aerobic sports, it seems cut more for climbers. On my admittedly scrawny runner's body with admittedly shortish arms, the chest is too wide (although the stomach is decently trim) and the sleeves are much too long. If you have a well-developed upper body and long arms, or like extra sleeve length for reaching, then this will work for you. For my purposes, i.e., running with just a thin shirt underneath, it's too roomy through the body and has too much fabric weighing me down in the arms. The three stars don't reflect the quality of the piece, just my disappointment at how this is cut for its intended use--high-output activities.