Lindsey Kunz wrote a review of Outdoor Research Helium II Jacket - Women's on April 16, 2014
Familiarity: I've put it through the wringer
This is the perfect lightweight rain jacket to stash in your climbing, backpacking, or skiing pack, or just clip onto your harness. It's so lightweight, you don't even notice you're carrying it! It has the OR armpit zips right down to your waist so it's easy to get some added breathability without compromising access to your rack on your harness. The lightweight wire in the hood also helps give the hood some added form for keeping the rain out of the eyes. I love OR's stuffing system on most jackets, including this one, where you can stuff the jacket into the pocket and use the loop and clip (or your own biner) to clip it to your harness or on the outside of a pack.
I'm 5'3" and about 135lbs and normally wear my OR jackets in a S, but go this one in a M to fit over my down jackets in case I need it for cold-weather protection. This setup works great and avoids me having to carry an extra jacket in the alpine.