Chris wrote a review of Patagonia Simple Guide Softshell Jacket - Men's on July 13, 2012
The breathability of the jacket is extremly high, but still it keeps the wind out an withstands an astonishing amount of rain before you get wet.
A must for people like me who tend to sweat a lot on a trail. I still have a packlite hardshell in my backpack on longer trips, but I am only using it in a downpour.
Layered with a 100er fleece it is warmer than "conventional" thicker softshells and far more versatile. And if you should get really soaked the combination out of the simple guide and a fleece will dry faster separately than a one piece thick softshell.
It is my number one go piece and it never let me down, come raine or shine or shnow and hail.