Alaskan Guy wrote a review of SmartWool NTS Microweight Zip Top - Men's on August 3, 2013
Familiarity: I've put it through the wringer
Fit: True to size
I'm 6' 0" and 155 lbs. I got the M and it fits great--slim enough to have a skin layer under. Great insulator for kicking around in 50-70 degree weather. Good in the 40s if you're active. I'd get a medium or heavyweight for winter activities, however.
Smartwool Merino is very soft and definitely repels odor. It's worth the price if you're serious about staying warm and dry. The antimicrobial qualities are what send this over the top.