I picked up the MED black one of these. Nice color!  I am 5ft 11in and 190lb.  I wear a 16.5 / 34-35 shirt and a 44L sport coat.  A medium Carhartt in any jacket fits me with room for a thicker sweatshirt-type under layer.  Sleeves are good length as well. I like the shirt tail aspect of this as it adds a little length to the jacket that is sometimes lacking in Carhartt (for me anyway). Great for 30 deg weather or above depending on humidity, wind and activity.  More jacket that shirt for sure.  Warmer than a hoodie.  Warmer than my light workout jacket.