I got a set two years ago for Christmas. I have worn it from about 50 degrees to really cold and I love it. I finally figured things out and went to all breathable clothing. The UA stuff lets the sweat move off your skin and as long as your other layers are breathable, it will dissipate quickly. If the knockoff stuff is of similiar quality, I would definetly go with it. If not, spend the money, they are good.