Rating: 5 / 5
The Patagonia R1 Balaclava has become a core part of my running and backpacking kit. While I rate it a 4 for running (because of one key reason explained later), I definitely give it a 5 for backpacking. Since we can't average the two, I decided to go with the 5 since this is a backpacking forum.
The R1 fabric is great stuff. I love it in shirts as well. It is essentially Polartec Powerstretch that has a grid inner fabric to take perspiration away from the skin and create dead air space for more warmth. I really love this stuff. The balaclava is lightweight for the warmth (just under two ounces), breathes well, dries relatively fast, and is comfortable next to the skin.
The balaclava fits very well. The front of it is nice because it works if one wants fabric over the mouth for added warmth or pulled down under the chin. This adds versatility. The neck part of it is long enough to offer full neck coverage. In addition, I often wear it as a sort of hat if I don't want face/neck coverage. This works nicely, too.
The one problem that I have with it is that the fabric over the mouth is as thick as the rest of the balaclava. This makes it pretty hard to breathe through it if I am sucking wind. While this is rarely a problem if I am backpacking, it can be pretty hard to get good breaths through it when I am running quickly up hills. While I see the value of this thicker fabric over the mouth (warming incoming air), I would like to see a somewhat thinner fabric to breathe through. This would make the R1 balaclava perfect.
This is truly a super balaclava if you don't need the absolute lightest. Its versatility and comfort are unmatched.