My bf wants a lightweight wind vest. He got the idea because I wear my Hind Spare-O vest running sometimes when it's cool and windy but not cold enough for a jacket. I have a couple of questions and need advice:

1. Sizing. I'm looking at PI vests right now -- and can't decide whether to order small or medium. He's usually a small in tops, but I took a surreptitious look at the tags of his PI cycling jacket and it's a medium, and seems to fit well. (I'm a small in PI jerseys and shorts but have to buy medium in their jackets, but not sure if men's cuts are at all similar). If you wear a medium in a jacket, would you wear a medium in a vest too???

2. Which one to get... I'm looking at the Optik vest and the Zephyrr vest. I'm leaning towards the Optik because it's more like the HInd vest that I have -- what he really liked about that one was how super light the fabric is. I have an Optik jacket and the fabric is really, really light but still does a pretty good job blocking the wind. The Zephyrr vest looks like it's more substantial, and more "constructed" -- which normally would be good, except, well, it's not as light. Does anyone have opinions on the trade-offs of getting one of these over the other?

3. ???? Other useful advice ????? Other men's vest ideas ????

Shopping for gifts is so hard. Arrgh.

Thanks!