Which windshirt for 3 season alpine touring?

I always do just wear the thinnest capilene base. It sure breathes well, but not so snow resistant when a branch drops its chilly burden onto you.

Unless I can find that jacket with some sort of stretchy or ultra breathable back it might be a good bet. I do have a pack on 99% of the time. The closest thing that I could find is the Patagonia Wind Shield but it sounds fleecy and possibly too warm.

I can't tell if something is going on at beyondfleece, since their order times are now 6 weeks (too much demand?), but they have also dropped a bunch of jackets they used to offer and features. So you can't get the dryskin jacket with a zip off hood (that is feature that I really wish I would have gotten, since for backcountry skiing I would really like to have a hood some of the time).

In any case, I also like to look at the climbhigh outlet, and have long thought of buying something from them (looking for the champ pants). They have pretty good prices, like the Gamma MX for $200, but also a bunch by Mammut. They don't have many of these in the shop in burlington, so I can't check them out in person. But worth looking at and comparing re: price. My take is that stock there can be limited and doesn't seem to change that much over time.

http://www.climbhighoutlet.com/browse/?tx_commerce_pi1%5BcatUid%5D=64&cHash=d45879310d

Beyond offers custom made jackets in Tweave Durastretch, their Steel offerings.

Tweave 521E has 25% stretch, is 6.5 oz./yard, unlined/fleeced, and very tough – maybe the toughest 'softshell' fabric around.

Wind resistance is good, with air permeability of CFM 23 – similar to Schoeller Dynamic, but tougher, and Schoeller Dryskin, but unlined.

For comparison, Pertex Equilibrium has CFM 10 (Stretch Equilibrium is likely more air permeable still, but no number is available), Polartec Powershield lightweight has CFM 12, Patagonia Houdini has CFM 5.

Patagonia Ready Mix and the new replacement, Ascensionist, also have CFM 5, but are supposedly as breathable as more air-permeable softshells due to their 100% polyester content and textured inner surface. But I've read on this site that the polyester fabric is less durable than nylon softshells. Patagonia claims, however, that this fabric is more durable and weather resistant than the Houdini.

I have had several windshirts

GoLite Ether

Marmot Ion

Patagonia Houdini.

I ski tour often and the Houdini was by far the bast. Breathes very well.

I just wanted to thank you all again for your insanely detailed advice. I ended up going for the Patagonia Traverse jacket and after a half winter of touring I can say that it is perfect. It's more air permeable than a wind shirt which is a downside when you are getting blasted but is a godsend 98% of the time. It breathes amazingly well and does a great job resisting snow and wind. As long as temps don't rise above 25 degrees or so, I put it on in the morning and don't take it off all day. The front zip gives a bit of venting if necessary and with a micropuff vest to layer on top the temperature range for going both up and down is incredible. Somehow it keeps the chill off while climbing without really insulating. I've bushwacked, skied powder and many others conditions wearing it and nothing else and have been very happy!

cheers