The shirt it's self  is well constructed. The stitching is strong and the cuts and contours are in the ideal locations allowing for full,range of movement without feeling like its pulling or tight, like under the arms whe stretching or reaching.
The venting is fantastic ad does help with overall cooling.
The ONLY drawback to this shirt is that it is way WAY t big for me.
I'm not a small guy, but not a manatee either. I'm 6' and weigh 190 lbs and I am swimming in the large, to the point that I gave it away to one of my fat friends and when he tried it on it even looked big on him and he is about 2 of me!

I don't know what kind of people run Columbia sportswear but they must be giants in stature.

My opinion of the shirt sands however. I liked it so much (despite the fact that it came as a tent, hahaha) that I ordered another on, only this time in a medium s I can keep it.