I love these shirts. I have the grey version and you can just slightly see my nips through it. Not a big deal for a guy, but girls might want to stick to the darker colored ones. They also don't last forever. No holes yet, but after 6 trips the fabric is showing some wear marks on the back and shoulders.
btw, It looks like Arcteryx just released a revised version of this. I think the fabric is different. (maybe stronger?)