I have referred to the skin-chilling effect of synthetic base layers here on a number of occasions; this occurs because of it's rapid wicking which tends to produce a cooling by evaporation, making skin feel colder.
Kutenay, you're the first I've heard say this. I came to the same conclusion from use, yet when I said so, some of my backprack friends clad in name brand synthetics looked at me like I was speaking heresy. Moving water rapidly away from skin lowers the surface temp of the skin: that's simple physics. It is also the biology of sweat glands. I still wear them for most of my hunting, but I'm seldom in extremes.
I think Rick Bin has it right as to our differences in preferences: he's not in coastal BC, nor is redmtn. I owned one pit zip mtn parka and have avoided that feature since. On a hike in the north Cascades of WA in early Fall, fairly dry climate, it was a nice feature however.
My rule of thumb for any sewn or stitched item for use in long term, unrelieved wet is the fewer opening the better, and the fewer seams and stitch holes etc. the better.
FWIW, musing through this thread has given me a tentative stab at another rule of thumb: If an area will grow any kind of pine tree, it won't be too hard to start nor sustain a fire.
I'm not yet sure whether that is true, but it is close. Maybe I just don't remember but I don't recall pines growing in the truly sopping wet areas that never dry out, like Ocean Falls, B.C.
This is a great forum and a great thread. I even bought some gear because of it!
Added a few minutes later: Looks like E and I crossed posts and I was typing as you posted.
One other thing I've noticed is how wet the outside surface gets on any porous outer garment when I wear a synthetic like Capilene as a base layer. That must partly be a factor of humidity because in drier air it would evaporate fast enough not to notice I would think. Sure wish I was out using the stuff instead of here typing today.
