I love this shirt! I am a medium and it fits exactly the way a "comfortable" medium should fit. It is not too tight in the arms, which is a problem I had with a Patagonia shirt in the past. It is not supper lightweight, but that also makes it durable. I have worn this under a sweater as a casual look and it looked great. I obviously wear it more for excersize and it is perfect for that as well! Ov
                    
This review was written in the old system and had content requirements that are different than reviews written today.