I purchased two of these shirts. They are very soft, light and comfortable. I wear them in a variety of high intensity athletic activities, including biking and running. As best as I can tell, they are similar to Ibex's U-Sixty shirt, except that Ibex adds 13% nylon to these shirts. I believe that helps them dry out faster than the 100% merino shirt. In any event, I like to see merino wool companies, such as Ibex, experimenting with different blends of fabric. The result in this case is a real winner. I am 5'8" and 145 pounds and the small fits perfect.