Epic as down garment shell

I don't have anything in Epic shell, but I have a Feathered Friends down parka in PTFE (Goretex knockoff).

It has absolutely no such problems as you fear.

–B.G.–

Thanks Bob,
It's specifically the Epic that is the source of my concern and maybe it's ill founded. See below:

http://www.backpackinglight.com/cgi-bin/backpackinglight/reviews/display_reviews?forum_thread_id=4730&cat=Shelters%20-%20Bivy%20Sacks&cid=34

I also have some 2-layer gore-tex that I was going to use to make a bivy sack that might make an attractive jacket shell. My only concern with the gore-tex that I have is that it's pretty stiff compared to Momentum 90 and basic 1.1 ripstop and might inhibit loft. Does Gore make specific fabrics for down? Like is "Dry-Loft" intended specifically for use with insulation?

The FF PTFE mentioned is more waterproof/less breathable than Epic… Gore used to market a material called DryLoft for sleeping bags, but decided to re-market that material as the Windstopper it actually is. Same stuff, no worries. More breathable than GTX. Epic at least as breathable, perfect for insulated garments like you're thinking. The 2-ply GTX you have would be less than ideal. Actually, the WS material is essentially 1st gen GTX; GTX now has a PU coat over the PTFE membrane b/c of problems they were having with the non-oleophobic nature of the original membrane and how it affected waterproofness. But really, none of this matters in this context. Use the Epic; it'll be great.

I have a pair of Nunatak Chugach booties in Epic and it has performed exceptionally well. No wetting of the down even after camp chores in the snow. I also have a BD Skylight tent and Wild Things Belay jacket and windshirt in the fabric and all are much better than water-resistant; I'd go so far as to say they are waterproof in the absence of an extended downpour. More than adequate for a down sweater that's used as a midlayer, or a sleeping bag outer fabric. I haven't used my Skylight in winter and can't comment on breathability. Didn't will Reitveld do a review of the Guiding Light based on winter use for BPL? That should have some useful observations.

I've a Nunatak Arc Specialist quilt and Feathered Friends Down Booties with an Epic shell, and haven't had any problems with moisture in the down.
I've also got an Epic shelled Wild Things Belay Jacket, and the thing is almost waterproof.

Thanks for the input everyone, and in the absence of any complaints to the contrary it sounds like the Epic will work great.

Also, I did find the Guiding Light Review you mentioned Richard, and the same comment was made about Epic having poor breathability in cooler temperatures. However, I'm hoping the warmth of a garment being close to your body will help minimize this, and as mentioned there don't seem to be any complaints surfacing about Epic jackets in cold weather.

I have a Feathered Friends Epic Hyperion jacket and have had no issues. In fact I have ditched all my traditional raingear and replaced it with Epic pants and jackets from Wild Things and a Feathered Friends Jackorack. Here in the intermountain west it works great in all but the heaviest longterm downpours.