Used the Capilene 2 Crew on a soggy and foggy trip in the Oregon Coastal Range. I'm 5'10" 180 athletic build and the M was good. Length was good. The material is somewhat stretchy so the shirt was form fit which is good for a layer. I liked not having an acre of fabric around my waist. The arm length of the shirt was good.
Temps were around 50, windy with showers, and I was comfy with a shell, the Cap 2 Crew and a sleeveless undershirt.
Definitely worth the $.