Not so good. Not at all.
- Gender: Male
- Familiarity: I've used it once or twice and have initial impressions
The Under Armour 4.0 shirts look great and have a great weight. Those are the pros.
The cons: The first drawback was the serious off-gassing from the synthetic material. I had to leave these shirts outside for a full two days because of off-gassing before putting them on. I would have left them outside a couple of more days, but decided to try them on before doing so. I'm use to synthetic off-gassing, but this is the worst ever. Really. There is also an itch factor with this shirt, along the seams and that shows up as the material presses against the body during movement.
Most really good or excellent base-layer shirts have slightly longer sleeves to cover important potential cold spots like wrists during movement. The Under Armour 4.0s sleeve length is quite short. When raising my arms overhead, as in climbing, the cuffs pulled back at least three inches behind my hands. Because the shirt is compressed tightly against the body, the cuffs stayed up on my forearms, leaving my wrists exposed. It almost seemed as if the shirt was to small but the torso length was good and the shoulders were perfect. I wore one of the shirts off and on for a day before deciding to return them and I will not buy another Under Armour shirt again because of this, as well as the cost of return shipping.
Also, no washing instructions came with the shirts, but if they are washed in warm or hot water I feel the itch factor may worsen. Other reviewers will no doubt provide insight. Too bad, seems like a great shirt gone wrong.