These shirts are great. I spent a month hiking every day and wearing long sleeves kept my arms from burning, but these weren't too hot, even in the 90 degree weather. If I was in a pinch I could wear the shirts multiple times without washing them and still not smell too bad. Basically the entire upper half of my wardrobe was composed solely of Smartwool...couldn't have been happier.
A couple of minor things - I wish they were less prone to snagging. I don't think there's much to be done about it, so I didn't deduct a star, but it's still painful to get a hole in your 60 dollar shirt (and all of mine have a small hole somewhere). I did deduct a star (probably only half of one if that was an option) because the left sleeve on my shirt always seems to twist around so the seam is on top of my wrist. It's fairly minor when hiking, just slightly annoying, but it's a little more of an aesthetic bother when I want to wear it somewhere other than the trail.
I really like the violet color (and it has a nice pointelle pattern). The natural is fine for layering under something, but it's a bit transparent on its own.
This was purchased for my niece. Here's what she had to say: "This shirt is a great top layer for a run on a chilly summer morning. The size small is form fitting (for reference I am 5'6'', 112 lb) and the size medium is a little looser. Both sizes would work great as a base layer in the winter, but the size small could go under my dress shirts and keep me warm at work without being detected. The fabric is soft and surprisingly lightweight for something this warm. I'd expect nothing more from Smartwool.
There is absolutely everything to love about these tops - weight is perfect for layering, wearing alone or sleeping in (I do all three); sleeve and body length are long enough to cover long torsos (I'm 5'10") and arms; style is flattering; wool is cozy and soft and can turn the worst day into a dream. Re: durability, I've washed mine over and over again with no negative (shrinking) effects. I air dry, but that's my choice - I don't think you have to.
I sit at a screen in a fairly cold office. I either layer up or freeze. This top slides under other tops. The long sleeves add warmth. The V-neck means that it doesn't show. My favorite combination is to layer this over a Patagonia capilene 1 tank and top with a long-sleeved sweater or heavier Smartwool quarter-zip top. Fits true to size and, like all Smartwool, launders well.
I love the 150g/m2 weight merino wear. This top is a great baselayer, and the black is substantive enough to wear alone. Honestly, for comfort, I prefer the Icebreaker Siren. It has more of a scoop next than the SmartWool V-neck. However, the SmartWool Microweight bottom is my favorite merino legging/long underwear. NOT ITCHY!
I love this top, I ordered a size larger than normal to wear as an outer layer. I've taken it kayaking. It keeps me warm when wet and dries quickly. I like the cut. It's a very attractive light weight top, best of all, I got it on sale!