chrp16990 wrote a review of Icebreaker BodyFit 200 Contour Crewe - Short-Sleeve - Men's on October 7, 2012
Familiarity: I've put it through the wringer
I'm 6' and 185lbs. I bought a large. It fits snug, but not tight. Just right for a base layer, but too snug to really wear on its own.
That said, a week or so ago I used this shirt without extra layers at the gym in the morning. It was so comfy and completely free of BO, that I decided to wear it all day. I kept it on to play volleyball that night. I'd soaked the shirt multiple times, but, amazingly enough, even after a fairly active 15 hour day, neither I nor it smelled bad at all. (Confirmed by my generally picky girlfriend. ;) )
Seams don't bother, even under multiple additional layers and a backpack.