Lizwrote a review of SmartWool NTS Lightweight Asymmetrical Zip Top - Women's on February 6, 2012
I love the side zip for xc or downhill skiing. I generally dislike the feeling of the front zippers against my throat, just still need the ability to open and close the zip as the weather changes. It does look a little weird open, but since I'm usually in snow pants or work out gear I'm not as concerned with appearance. The thumb holes keep snow from getting in under you gloves.
The wool is super soft against the skin and will still keep you warm when you stop after working up a sweat on a tough section of trail.