I have a KOM wool jacket and a Sleeping Indian Designs wool shirt. I used them both on a recent deer hunting trip in New Mexico in early January, where the temperature varied from about 15 - 55 degrees, depending on the time of day. I started in the early morning with both of them on, and by mid afternoon I wouldn't be wearing either one. It didn't occur to me before the trip that I would ever be warm enough to not want either one on, and I should have also brought along a cotton camo tee shirt.
As far as quality, they are both top notch. They look like they both could have been made by the same company.
I ended up ordering the shirt from Cabelas on a close-out; otherwise, I probably would never have bought such an expensive shirt. They only had medium left, and I ordered it thinking I would send it back if it was too small, or maybe if it was only a little too small, I would keep it to encourage me to get down to my correct weight. But it fits okay; a little snug, but they know you're going to be shooting with it on so there is plenty of arm movement. A little snug is good, really, as it fits fine under my larger KOM jacket.
I don't really seem to have any problem shooting with either the snug shirt or the slightly loose jacket, but of the two, the snug shirt probably works a little better. I am concerned about what will happen whenever I have to wash the shirt, as the sleeves are just right as they are, and I wouldn't want them to shrink any. Maybe I'll have to dry-clean it.