It wasn't that long ago when if you needed a lightweight warm jacket to take to the mountains you would go for (goose) down, But things have changed in the last few years with the advances in Synthetic's, Companies like Primaloft has changed the game and we now have 2 choices and there are good reasons for both, Most down are from Goose, The down is not the actual feather but rather the fluffy bit under the feathers,You can get a mix, Mother nature is hard to beat when it comes to insulation but here are drawbacks to using down, On the plus side its very light and compactable which is important if you have far to carry anything, The negatives with using down is that it doesn't stand up well when wet, The down clogs up and you loose heat i.e you will get cold, Synthetics on the other hand hold body heat well even when wet and the fibres that make it up stay in place,Not everybody can use down as they have allergies and this is another plus point for synthetics, So if you are trekking in cold dry conditions then got for Goose Down but if say you are heading to Macchu Picchu or the Smoky Mountains where it can be cold but damp/humid then a synthetic jacket would be the better choice, Synthetic jackets also dry much faster than a Down jacket.
The high altitude summit style of jacket currently will be 800+ fill Goose and i am interested to see if over the next few years if that will change
Working for The North Face i get to see and try all the new gear, Their top of the range Mountain gear is called the 'Summit' series and goes L1 to L6 with the L being the layer, There are 2 styles of L3 jackets, 1 in Goose and the other a synthetic named the Ventrix, In the same market as the Ventrix you have the Patagonia Nano air and the Arcteryx Atom of which i have both, All 3 jackets are super comfortable and have a 4 ways stretch to the material making them great climbing jackets, I think the Patagonia Nano air was the first in the market, the Northface Ventrix has a couple of tricks up its sleeve so to speak, You cannot see it but the material inside the jacket when made goes through a roller that puts small slits in the material under the arms and in the Summit series down the center of the back, When you are stretching like when climbing the slits will open letting excess heat dissipate and when you are back in a normal position the slots close keeping your body heat in, All very clever and something you cannot do with Down, So there you have it, Always nice to have choices but now you have different styles of jacket for different conditions
Dave
