Great base layer for cold weather aerobic activity
I use this as a base layer, underneath either a windbreaker or a long-sleeve t-shirt, for running in cool to cold weather. I am very happy with it. I like merino wool base layers primarily because they don't pick up sweat odor and can be worn a few times between washings (a nice feature when wearing for running twice a day every day). Note when I say "fits true to size" that the product description says it is "form-fitting." I am 5'10, 145 lbs, 38-inch chest, 32 sleeve, stereotypical "runner build" (large end of "small" on size chart), I bought a small, and it fits me basically the way it fits the model pictured (i.e., tight like the typical Under Armour "compression" fit). I have not found this to be itchy at all. Although the product description includes "moisture wicking," I don't find this (nor any other merino wool) base layer to actually keep me dry during intense running; however, it still keeps me sufficiently warm even when working up a sweat. I find synthetic base layers (polyester or polypropylene) to keep me more dry than this, but I still find this to be at least as warm if not warmer (and again, for me, not stinking of sweat is the key feature). My only question or doubt is the durability. I've only had it for a couple weeks, and it's so thin that I just can't help but fear that I'll rip it when I'm taking it off (again, it's pretty tight). It is still in good condition and shows no wear, but I just can't help but wonder how something so thin and "delicate feeling" will hold up over time. It comes with a lifetime warranty from the manufacturer, so I'm not too worried about it.

Great base layer
Love the functionality of wool over synthetics. This is comfortable next to skin. The wrist is great - stays in place / tight to skin withotu any bunching under additional layers.

this shirt made winter sailing comfortable
As a college sailor on Lake Michigan, keeping warm when there's ice in the boats is expensive and often uncomfortable. This shirt changed that - now I'm always comfortable. It never smells, so it is perfect to layer underneath warm sweaters and wash once a month. It's perfectly breathable, so it always keeps me dry, even under a chunky drysuit. Best part is how comfortable it is -- just like having a soft blanket woven around you at all times. It really is an all-year piece of clothing, and though it's a bit of an investment, it's the most versatile high-performing fabric out there.

Thin, lightweight yet warm. Excellent base layer. Very comfortable unnoticeable. Doesn't seem to retain sweat odor. I have already purchased other Ibex products. Would definitely recommend.

Warmer than the synthetics without any itch. Worked well in trips to the mountains.