Yep, I now have to agree with this. All last winter and up to yesterday I'd been using various UnderArmour type shirts as baselayers. They worked ok but soaked up a lot of sweat. The real problem is that they'd get really cold if I took even a short break and then would take forever to get warm again.

Finally picked up my first merino wool baselayer shirt and wore it yesterday for a 30+ mile ride in temps of 7f. The shirt moved the sweat very well and I never got cold even when stopping for a couple of minutes. Very impressed and will now be looking for more wool to use as the temps are only going to get colder here as winter sets in.