I've worn their shorts for years and personally found the cheaper Ex-Officio boxer briefs just as comfy. But their helmet liner with the long tail (protects my neck from sunburn) and their long-sleeved shirt function remarkably well! If I wet the shirt on a hot day it feels like the temp drops 20 degrees once I get going.
I think the difference in my experience with the shorts is that on the GSA the weather protection is so good that evaporative cooling of the boys is minimal, whereas the shirt has a lot of airflow that keeps things cool. It felt really good!
I got a sidecar to travel with my dog. He never complains, is delighted to be with me, approves of my dietary choices, is a social butterfly who helps me meet folks, appreciates a good beer, snuggles better than my wife, and hangs on my every word as if it's the most profound thing he's ever heard. TravelsWithBarley.com