Sierra Designs has decided that carbon based life forms deserve carbon based clothing. They've partnered with Cocona to produce what you could call either a hard soft shell or a soft hard shell, depending on how you see your glass. The very wearable Jive jacket uses Cocona's xCellerator fabric, which is derived from coconut husks and has a very soft hand while providing highly breathable waterproof protection.
The lightweight (one pound) Jive makes all the right moves. The reach-across chest pockets don't interfere with your pack's waist belt, and they have mesh backing so they partner effectively with the pit zips to vent your next-to-skin nastiness outside to where your partner can enjoy it. The pit zips start just below the pit and extend to the elbow; at first we were worried that wasn't sufficient venting but it seems to work just fine, probably because the fabric itself breathes so well. Also, pack straps usually get in the way of pit zips that go farther down the torso so the design makes sense.
The hood is helmet compatible, although wearing a helmet does cause the hood opening to ride up over your chin, especially with larger volume helmets like the Petzl Meteor III. Oddly enough we liked that just fine, and the hood is articulated enough that it provides excellent visibility side-to-side. We're very particular about hood design around here, and we really liked the lay-flat design of the Jive's hood, and the fact that the fairly trim opening kept the elements out even while open.
The microfleece zipper guard rests comfortably against your chin, and the rip-and-stick cuffs, hem and hood drawstrings provide ample adjustments. There is a left bicep pocket that is just tad too deep as items fall around your elbow, and an inside left zipped pocket on the chest. Performance is great; light rain sheds quickly and heavy downpours stay outside thanks to the waterproof zippers and fully taped seams. Breathability is good while buttoned up and great when fully vented. There's minimal clamminess if (when) you overheat, nothing that a light wicking layer – which you're wearing anyway, right? – can't easily handle. Built for backpacking, Sierra Designs bills the Jive as a 3-season jacket. We think they're selling an excellent jacket short, and there's nothing to prevent it from doing winter alpine duty as well.