I too have been using the UA products for several years. While it is "tight," it has helped to feel more like a 2nd skin and keep my back warm and loose. As a +50 aged player, changing weather can mess with my back, so this use of multiple layers has helped me a great deal.
This new FJ system will surely up the stakes in this type of dressing. I know many FJ folks here have been hoping for something like this for quite some time.