Got to agree with everyone about how well they look, especially when you throw off the outerlayers. I received these in Afghanistan during a rather cold day and switched from the polyester blend liners I had on to the Patagonia Capilene 2. I gave it a go at just wearing the layer and worked out pretty well in the 40 degree temps. I was still chilly but not too bad. Its definitely not a wind breaker but provides great insulation when I wore it with mine.
I thought it was too flimsy at first but I did buy it bigger and that'll help I move around in it. I slept in it last night in our 60*F b-hut in a synthetic sleeping bag and was comfortable all night. Did not wake in a sweat or shiver. I've got it on under a polo now and it looks pretty good, IMHO. Defintely a good buy and highly recommended.