Like my IceBreaker leg thermals this top is equally as excellent.
During a lengthy excursion in Banff, AB, Canada in conditions with wind-chill as low as -36° F I was kept warm at the skin protected by a fleece layer and a good Northern Face guide jacket.
In warmer conditions the product worked equally well during a full day of play in temps between 16° F and 28° F.
I found the product fit well, stretched and moved with my body as needed and was easy to put on and later remove.
Overall in the conditions described above I rate the product a 10 of 10.