I purchased this shirt at the same time I purchased Janji's Helio Tech Tee. My primary use case for these is exercising in hot summer weather (primarily inline skating, hiking, and biking), and later this year, I intend to use them during winter activities like backcountry skiing. Both of these shirts perform far better than your average T shirt in hot weather scenarios. However, I think the Helio Tech tee does a better job at 1) doesn't cling to body, 2) dries almost immediately, whereas the Merino Repeat Tech tee remains sweaty-looking for longer, 3) the Helio feels a little cooler temp while exercising (although the Repeat is no slouch in that department, either), 4) the Helio seems a little more odor-resistant, and 4) the Merino Repeat Tech's price is higher (TBH, if I hadn't gotten it on sale, the price might have been prohibitive for me). But I also want to note: 1) the Merino Repeat Tech tee feels super nice on the skin, and if you weren't exercising, I'd say the Merino feels nicer than the Helio, 2) the Merino seems like it might be better than the Helio once fall and winter arrive; in scenarios like backcountry skiing, where you are sweating on the uphill, but then need to retain warmth after you stop moving, I think the Merino might do better at that, and 3) I did mention the cost of this one, but if this shirt lasts for a long time, it will be totally worth it. Time will tell. So far they've seen a solid month of heavy use and they are holding up. In the meantime, I love Janji's style, ethics, and their sling bag kicks a**. Def worth trying these out.