This my second PB Jacket after having purchased another, earlier lighter version (don't remember the name) that had Gore Windstopper incorporated into the design. The jacket still preforms exceedingly well with nothing underneath but a mid-weight LS shirt in temps in the single digits with kickin' 20kt gusts. Not the smartest approach, but I was able to be comfortable enough to concentrate on what I was doing, not how stupid I was. Not the most compressible piece of kit I own, but I'll gladly sacrifice a bit of space for a good backstop anytime. Also, while it's not a suit of armor, it's survived a number of spills crossing icy roots and dirt, as well as unintended run-ins with trees, and has come out with only minor abrasions. Hang on to this particular design for a while OR....I'll be back!