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.
Now, it seems that Eremicus finds this true of wool, which is not my experience and I have never heard this from anyone using it. Funny that he has not mentioned this prior to now, must not be mentioned on the Patagucci label or promo material, I guess.
Concerning pitzips, of course they will vent body-warmed air, that is their major purpose and when excessively heated as with rdmtn's Caribou packout, they do help to cool you off, but, they will not vent all of the moisture or prevent cold water entering at the part of your body most susceptible to heat loss due to a lack of fat-muscle insulation, most heads excepted, of course.
Merino wool, not just any wool or blend, will work with eVent shells better in severe cold and in extreme wet, as well. I own and use both and have for years, the pitzips simply are extra weight and bulk and are rather inefficent technology compared with merino/eVent.
Synthetics work OK in moderate conditions, but, spending a week or more in the same base layer will soon teach you the overall superiority of virgin merino, especially Icebreaker. With this, I now do not have to carry a spare undershirt and only one spare gonch plus a pair of spare socks...a weight saving important to a 60+ backpacker.
