I thought this product was overpriced, that is till I got it and compared it to my wife's merino from a big box store. Her's was mostly polyester. The shirt has helped me fight off one of the coldest winters in Michigan history (granted not the shirt alone). It is super comfortable, didn't seem itchy for the few hours I've had it on but I've not yet wore it hiking over a long period, I ordered a medium and I'm 5'11"\165#. Fits pretty well in the waist and shoulders, a little big on the arms but I suppose I'll just need to work on my guns a little more!
"This is the best piece in my clothing kit"
-I use this in winter and summer (and in between)-it's used as my baselayer with, maybe, a softshell over it and a hardshell if the snow is wet (I live in the PNW-great wicking ability and keeps me warm in the dead of winter during BC skiing. Even in -10C or 14F it is amazing how warm you remain (I do run hot)-in the summer, it wicks beautifully and is super thin so you don't overheat-this is one of my best pieces of kit
Nota bene: Merino is costly and demands an investment, so I bought the Merino 2 on a ridiculous sale. That said, if you're willing to pay up, this will pay off. The merino/polyester blend is isn't quite as soft as pure merino, but it wicks sweat and holds up better over time (especially if you're planning to run it through the wash). I usually wear a S in Patagonia, but I got an XS as a close-fitting baselayer. I wouldn't recommend this as an independent 1/4-zip unless you have a substantial tee under it (the material is pretty thin). But it captures body heat, and the zipper is really lightweight, so I layer it under an R1 or softshell for cold weather hiking.