Short sleeves means this version has all-season versatility. Just like the sleeveless version, you'll get fantastic sweat-wicking -- essential for staying comfy in any season. Temperature regulation starts with dry skin, and Giordana's base layer gets it done with reliable efficiency.
I have the sleeveless and long sleeve versions of this base layer. I'm 5'7", 140lbs, and the small fits well next to my skin, but isn't uncomfortably tight. While other base layers use more technical fabrics, the polyester material this piece uses is comfortable next to your skin, and effectively wicks moisture away. I've used the long sleeve under a Gore Phantom jacket and been comfortable in the high 30s, and have used the sleeveless in 80 degree weather under a short sleeve jersey.