I have a selection of ice breaker stuff. I have 140, 190, 200, and 260g/m2 tops and 200 and 260g/m2 bottoms.

Year round I favor the 140 and 190 tops...short sleeved ones. For any medium to high activity in the winter I favor the 190, with the 260 for low to no activity.

Bottoms I always prefer the 200 over the 260 unless it is very cold.

I have worn fishnet from Brynje covered with 200g/m2 icebreaker or smartwool in very cold conditions and find that combo near perfect.

Ice Breaker is fine stuff and has completely eliminated all poly tops for me. I never wear capilene tops anymore under any conditions. I do still wear capilene bottoms for high activity or just under surplus wool pants so they do not sand my ass off.

If I was only going to buy one layer it would be 200g/m2.

Ice Breaker can sometimes be found for very good deals at Sierra Trading Post. I bought nearly all mine there but would not hesitate to pay full price for it....it is worth it.

The best thing about a thin merino layer is that it does not feel at all clamy when damp from sweat...it does not wick that moisture right into your next layer wetting it forever, it dries more slowly on your body rather than a layer of moisture sitting on top of the stinking poly to evaporate rapidly chilling you to the bone. Many times I only wear a top when x-country skiing....merino top is vastly superior to poly tops for this rapid cooling. They are also superior in my view in keeping your midlayers from getting soaked.

Pure heaven is skiing with a 200g top, stopping adding a 260 top, and a wind breaker...you are instantly comfortable and the mid layer will not be like a towel soaking up all that moisture on the surface of your top.

Fishnet under a zip top is heaven too.....open that neck and vent, zip, add a layer and windshell and you are warm and dry in very cold weather.

Check out Sierra Trading Post....Ice breaker is top end stuff. Dump the stinking poly tops...