Summarised (plagiarised) from http://cmc.org/cmc/tnt/978/gearguy.htm as retrieved on 22 Dec 2004 .
The jackets, not the crabs. These relative newcomers to the outdoor clothing scene have earned a well-deserved and central position in many people's outdoors clothing arsenal.
Back about 1997, I overheard some mountain guides talking in hushed tones about a new miracle fabric from Switzerland that was warm or cold at need and stretched to accommodate even the most extreme movements. Of course at the time I, like everyone else, knew that all you needed was some polypro, some fleece, and a Goretex parka.
A year or so later, I was at the field day for an avalanche class in some nasty weather conditions. As we left the trailhead, I noticed that, while the whole class was wrapped in Goretex from head to toe, the CAIC instructor was wearing some double-knit-looking jacket made by Cloudveil. 'Hah!' I thought; 'he's going to be wet and cold in no time.' Funny thing was, while we were all venting and stripping layers about fifteen minutes up the trail, the instructor wore the same jacket all day and seemed quite comfortable. Hmmmm, this bore some investigation. So, that's how I came to the softshell revolution, and I haven't looked back since.
My first softshell piece was the same Cloudveil Serendipity jacket that the avalanche instructor wore (well, not the same jacket), and it was a miracle. Layered over my windshirt, this jacket was all I needed, except in the coldest and windiest winter conditions. When moving fast, I never overheated; when I stopped, I never got chilled. The fabric, Schoeller's Dryskin Extreme, repelled all but the most persistent downpour and wet snow. The Serendipity jacket is what really put Cloudveil and the Schoeller fabric line (that magical Swiss mystery fabric that the guides were whispering about) on the map in the U.S.
Ninety percent of the time, at least in a continental climate like here in Colorado, you don't need a 'hard shell' (what Goretex and other 'waterproof breathable' shells have come to be called) jacket or pants. Only a determined downpour or steady gale-force winds require that level of protection. The rest of the time, breathability is tremendously more important that waterproofness.
Softshells have also truly enabled the revolution in lightweight hardshells. Since they now aren't worn as often and have only a limited function to perform - keeping out intense rain and wind - hardshells can compromise somewhat on sturdiness and thus weight.
When we're hiking, climbing, or skiing, if we've layered our clothing properly, our body heat pushes moisture (sweat and modest amounts of precipitation) out through our clothing to the surface where it can evaporate. If our clothing can't keep up with this moisture transport, we get wet, clammy, and cold. Softshells excel at this moisture management.
It took a while, but after the wild success of the Serendipity jacket and companion Symmetry pant, other manufacturers began flinging themselves onto the softshell bandwagon. Today, many companies are offering only one or two hard shells compared to numerous options in their softshell lines.
Although Schoeller was the first stretch-woven fabric on the outdoor scene, a wide variety of fabrics with varying degrees of stretch, durability, moisture resistance, and breathability are now available from Schoeller (dryskin, dynamic, skifans, etc.), Malden Mills (Polartec Powershield and Powershield Lite), and Ibex (Climawool and Climawool Lite).
Despite my love affair with my Serendipity jacket, I set out this winter to find something just a bit warmer, and that is the genesis of the review that follows. [The following has been significantly reduced as the models are all probably now obsolete - RNC]
Some manufacturers have evolved softshell fabrics to be more wind-resistant in order to increase warmth. In the case of the Polartec Powershield in this jacket, they took it one step too far back towards the old-school 'waterproof breathable' (WB) fabrics. For someone like me who sweats a lot, this fabric simply doesn't breath enough.
This became very apparent last Feburary, when Mrs. GearGuy and myself were out on a sub-zero day to climb Mt. Guyot. At our layer-adjustment stop, Ms. GG had sprouted a small forest of hoar frost all over her Ibex softshell, while mine remained free of such adornment. Later in the day when we got back to the truck, the inside of my Gamma SV was coated with ice; just like the bad old days of WB fabrics. This would probably be a good winter jacket for someone who emits less moisture than I do, or for less aerobically-taxing winter sports.
The Gamma MX series uses a thinner, lighter, more breathable version of the Powershield fabric, and the comfort level is correspondingly higher. The hood is a nice addition that allows convenient fine-tuning of your comfort level if you're starting and stopping a lot or if the wind picks up and you don't want to stop and put on your balaclava. It wasn't quite warm enough for what I had in mind though. I expect, however, that it will occupy a prominent place in my closet for most of the year due to the many nice features that it has.
The matching pants are, hands-down, the best cool-to-winter-weather pants that I've ever owned (and I've been quite keen on some others; see below). The added windproofness of the Powershield fabric is ideal for pants since legs tend not to sweat as much as the torso during heavy exertion. Due to the added wind-blocking power, these pants can be worn without a base layer in some fairly cold and nasty conditions. The smooth fabric surface sheds snow like Teflon.
The Icefall is the jacket that allowed Mrs. GG to sprout her coating of icy feathers on the way up Mt. Guyut, which is testament to the significant moisture-moving capability of this jacket. Ibex has added wool to their stretch-woven blend to create 'Climawool' which seems to have all of the benefits and none of the drawbacks of traditional wool garments (ie no smell when wet or scratchiness when dry). Early models did have one of wool's drawbacks; they tended to 'pill' when washed. Ibex seems to have tweaked their weave or composition successfully since then, and recent garments have much less of a problem in this regard. [But wool still takes ages to dry properly, while most synthetics dry quickly. RNC]
Final advice: