This discussion has been a bit of an epiphany for me. I used synthetics and wool/syn blends for 10-15 years. About 2-3-4 years ago I switch to all merino wool, not just any merino but the thicker versions (Ice Breaker 260 specifically). I've had 'mixed' results and it wasn't until Form posted and I started thinking about the issue that it became clear to me. For eastern TS sitting, the Ice Breaker 260 works excellent - not much walking, therefore no sweat, I stay warm and dry. The issue starts when I get into the hiking and sweating, then sitting that I've noticed the cold issue which is new for me. Thought I was just getting old. Putting the old part aside, my base layers were/are not drying out in the humid east unless I was able to maintain a enough body heat to do so. That's take 2-3 hours at times. Sitting in 20-30 degree temps with a wet base layer is what's making me prematurely cold. The give away is my legs and feet. I didn't develop a soaking sweat on my legs or feet, therefore they stayed warm while my upper body got cold. I knew something wasn't quite right because this is opposite of my entire life experience in cold. I was born and lived in NW PA for 40+ years, so I know cold weather.
Wearing the 260 in the west has kinda worked mostly because of less humidity but I've still gotten cold after a strenuous hike in to sit for a morning or evening.
When I recreational hike, I've noticed the same issue when I wear the Ice Breaker 260. I've worn an Outdoor Research shirt (80/20 syn/merino) that is probably 120-150 weight. It gets soaked hiking but dries fast. It dries in the length of time after I take a break and put on a puffy of some sort. Viola' warm and toasty after a brief sit.
I ordered a FL Aerowool shirt yesterday and dug out my OR lightweight syn/wool shirt. I'm wearing them hunting next week - lots of hiking, still hunting, sitting. We'll see what works.
As an aside, check out the Polar Tech website - they have pretty good descriptions of their products. I'm really curious about their Power Wool product. I'm trying a merino/syn mix first because I really like the feel of Merino against my skin. I'll trade a few extra minutes dry time for comfort - at least for the moment.
