I am obsessed with this bra, which is saying something because I usually avoid bras at all cost. This one, though, is simply amazing. First, it's super cute and the colors are awesome. I also really like the cut of the bra -- not too wide shoulder straps and relatively low-cut bra, so that it won't chaff on your upper chest or look weird under a shirt. Second, it's incredibly comfortable. The wool is soft and light-weight. And, wool, being the magical fabric that it is, keeps you cool when you're hot and warm when you're cold. It dries quickly and is anti-order.
I wore this bra for SEVEN DAYS on a desert camping trip throughout southern Utah. I took a couple dips in the freezing water in the Narrows and the Fremont river, sweat like crazy while hiking around...and this bra was perfect. It never smelt, never stayed clammy or wet and was so comfortable. I forgot that I was wearing it and was never uncomfortable.
The only reason that I didn't give it five stars is that the sizing is a little unique. I have both a small and an XS. The small is a bit loser around the armpits, just because it's wool, but the band is nice and snug. I didn't love the small for high-impact sports like running because it moved around a bit, but the small was perfect for backpacking, hiking, climbing, etc.
The XS feels a tiny bit snug around the chest band, but the wool also sits close the chest and is tighter in the places where the small was loose. I use the XS for high-impact sports where I don't want any movement in my baselayers. Also, if you're looking for ultralite and or minimal sports bra there are tags inside the bra, which could lead to chaffing.