I've been returning over and over to the size chart on this one and I feel that it's a toss-up between the medium and the large. At 6' and 175 lbs, I feel as though I could go with either size depending on preference. I would really prefer a trimmer fit, but the dimension of most concern to me is the shoulder width as this jacket comes up narrower in that area than other IH jackets I own.
For those that decided to go with a smaller size: Do you find that the smaller shoulder size is not too constricting? I figure that the longer sleeve length may help to compensate for concerns in that regard.