Hey Mike:
I used their shirts when they were first introduced in the late 90s. At that time they were hot for southern climates and the year after they introduced a lighter material. I never tried it. Also, they did not offer a tall size, so the main problem was the sleeves were too short for me. They’ve been around a while now, so maybe they’ve addressed these issues. Their bellows pockets seemed overly large and got in the way when my hand would brush down and catch the opening of the pocket.
I use the Columbia Bahama nylon shirts now. If I’m concerned about color on high sun days, I’ll wear olive.
If you wade fish small streams or perhaps flats areas where stealth is important I can maybe see the advantage.