I have mixed feelings about my cool wings.
The first time I wore them, my jersey (not new by any means) somehow bled onto the cool wings and stained them in a couple places on my back (have NO idea how/why that happened). I didn't wash the cool wings first, so maybe the newness of the fabric had something to do with it??? Who knows. Now they're mostly white with pink spots.
I still have to wear sunscreen underneath them. The first few times I wore them I didn't and still burned (I burn fairly easily, tho). I think when it's very warm outside (80-90's) they are cool and quite nice to wear. When it's blazing hot (100's) they are too hot for me. Even with pouring water on the arms to keep them cool, they are too hot for me when the temp gets near 100. I prefer to be sleeveless then.
Overall, I really like them. Don't wear them as much as I'd like because I don't have lots of sleeveless jerseys and don't like them paired with my short sleeve jerseys.