If it helps with sizing, I've had one of these shirts for about 15 years and am 5'8", currently about 220, but this shirt also fit when I was 175. These are amazing shirts! They are warm when you're outside, but stay cool and comfortable when you're inside. Comfortable through a wide range of temperatures and always look good - they don't take wrinkles and always seem to hang nice - and as I already mentioned, they last forever!
If you're wondering why I haven't bought these already, it's just my lousy luck and bad timing. I just got back from Laughlin where they have an outlet store. These shirts go for $99 on sale at the outlet, and I just paid $139 for a slightly different version I got to give "Old Faithful" a break once in a while. This is a screaming deal! Somebody help this guy out, you will be really glad you did!