I love the new relaxed fit 100% merino women's tshirt! The fit is tts; I take the same size (medium) as the women's 100% merino short sleeve shirt.
The big differences, I find, between the two styles in the fit are that the relaxed fit has: higher crew neck (AKA this also means smaller opening), shorter length (top to bottom), and wider in the torso (or straight cut from the chest down). On me the two fit the same in the shoulders and the chest. All this to say that I like both styles and I'm glad to have another option that works both for outdoor activities and travel.