Pros: Fabric feel, comfort, warmth, sweat handling, price versus other wool brands
Cons: price versus comparable synthetic tops.
I've seen ads touting Merino wool over synthetic fabric as a base layer, but didn't give them much credence until trying the Minus33 mid weight bottoms and 1/4 length zip top that I recently purchased. Wool costs more than synthetic and normally I went for what looked like a bargain. However, I had a chance to pick up some Minus33 base layer clothes at a price just a little higher than a good synthetic version and decided to give it a try for the ski season. I'm glad I did. I haven't had a chance to try them in a full winter onslaught yet, but I was able to use them exercising outside on a cold, windy day and they performed well and felt better than any synthetic version I used.
I purchased this Minus33 crew neck top base layer, a 1/4 zip mid weight top, and some Minus33 mid weight bottoms in the same purchase. I've tried them all on for fit and comfort, but have only used the 1/4 zip and bottoms so far. However, 1/4 zip and crew neck are similar enough that the information below from the review I wrote for the 1/4 zip should apply to the Minus33 crew neck as well. The weight of the wool and comfort of the fit are the same between the Minus 33 1/4 zip and crew neck tops
The Minus33 1/4 zip top and accompanying bottoms performed well the one chance I had to use them so far. I wore them to take a run when the temperature outside was tool cold to just where shorts and and a t-shirt. I wore the bottoms and the top with just my running shorts over the bottoms and felt comfortable temperature wise for the whole run. I never felt too hot, even though I often build up a lot of heat when I run and I never felt cold either. The 1/4 zip top and wool bottoms helped keep me in a comfortable range.
Once I finished my run, I got to be impressed by some other qualities of the wool. First, I sweat a lot when I run and this run was no exception. But, I didn't feel particularly sweaty during the run. When I got in and took the bottom and top off, I was able to see that the wool had absorbed a lot of sweat from me kept me comfortable despite the sweat. Next, the bottoms and tops dried fairly quickly and didn't smell at all, even the next day.
There only small negative of the crew is the price. Wool is more expensive than synthetic and if you compare the price to that of a quality synthetic brand, it is going to cost more. However, if you price it against other premium wool base layer brands, the Minus33 clothes can be found for less, and are thus a good value compared to other wool brands.