I have the Performance Transformer jacket
http://www.performancebike.com/shop/...tegory_ID=1130 . I've used it in the rain a number of times and like most breathable materials water will penetrate it after a few minutes of rain but not enough to get you soaked. What I really like about this jacket is how I can remove the arms and still wear it as a vest for those days when its humid and still drizzling a little bit. I tend to stay away from the one piece jackets cuz it'll keep me dry from the rain but gets me soaked from my sweat.