Top 3 favorite in base layers
I have several different base layers, and this one is in my top 3 favorite. I love the Patagonia capilene line. Each is different and has it's own unique feel and features. The capilene 3 is designed for cooler weather. To me it has a different feel than the cap 1 and 2. But like the other 2 it is very comfortable. Its light insulation kept me warm in temperatures ranges from 40 to 60 degrees. If it's much warmer than that I'd use the cap 1 or 2. If it's colder than that I'd use the cap4. I like the fit, but the 2010 and 2011 versions have a little different than the 2009 version, in that is a little looser, which I personally like. Around the arms and wrists it fits ever so slightly loose. But not so much that it would seem baggy or not insulate. The cap 3 is 100 percent polyester, meaning it is obviously made of synthetic material. When I compare it to merino wool, I think it is just as comfortable but it is much more durable, and is much less expensive. So I tend to buy more synthetic base layer as opposed to natural base layers. I really like the 2011 colors. Once they go on sale or if this review get approved, I might buy some more

Good warmth to weight
Capilene is a standard for a reason. You get solid performance both in warmth and breathability for light weight. I particularly like that this shirt does not have seams across the shoulders and that the finish is slightly brushed, which gives it a little extra warmth. The large was just perfect for me at 6', 190. Getting a little warm to wear it now, but a great shoulder season shirt for your clothing system.

cap 3
First time purchase of a capilene product from patagonia. I now understand the loyal following. Purchased this top and bottoms in #3 to use for fly fishing trip in early April this year. River was still chilly and mornings and early evenings were cool so this was the perfect baselayer for those conditions. I ordered 2x top and it fits very well. Plenty of sleeve and body. Garment moves very well and I will say I like the offset seams on the yoke of the top. Its functional not only for packing but I think it adds to the flexibility of action when casting or paddling or other movements. Product is warm when you need it to be and remains light enough if you shed some layers during activity.

Great Shirt!
I bought the Patagonia Capilene 3 because I needed a versatile long sleeve base layer for spring, summer, and fall backpacking. The shirt has been great! It has a nice fit and provides a perfect layer for those cool days where a long sleeve shirt is needed (or if in buggy conditions) but still warm enough that you don't need a coat, jacket, or fleece. When the conditions are even cooler this layer provides a great layer to have on under a small jacket, coat, or fleece. Even in warmer conditions this shirt still breathes incredibly well. I would recommend this shirt because of its great build, and most important its great versatility. I don't know how you could go backpacking without one!

Great shirt
Bought this shirt for vacation in SoCal when it wasn't quite warm enough to wear just a t-shirt. Awesome shirt! Kept me warm but not too hot. Came home from vacation and bought a second one. Great stuff!