I like Merino wool products a lot. This has been mentioned in other reviews and forums. They wick well, keep you dry when wet and have virtually no reek like synthetic baselayers.
A few weeks ago, I purchased two of the Icebreaker Tech Tees and I began to wear them around town. Being that I've worn Icebreaker midweight Zip T's, I was familiar with the quality of the baselayers.
I ordered another Tee, the Hopper, and washed the shirt as recommended (Sport Wash, inside out) and wore it for an eight hour hike and climb of two 14ers and tough connecting ridge. The baselayer worked well to protect me, keep me warm in the early morning chill and dry when I began to sweat in the Colorado sunshine.
The negative that I experienced was the pilling of the upper back of the shirt where it came in contact with my close fitting backpack. After I removed it from the washer and line dried it, I saw this pilling of the wool.
This was the first time I've ever seen pilling after only one time of wear. Perhaps this is attributed to the Superfine wool, I don't know. I have two other Superfine shirts that I doubt I will wear with a backpack. This goes against the nature of the baselayer and I'm at a loss as to what to say or write.
I like Icebreaker and will continue to use their baselayer wools. I returned the Hopper for credit and kept the other Tees. I also informed Icebreaker as to the problem.