I've got 2 merino jerseys ... one short, and one long. I've also picked up a few Merino t necks as base layers. I really like them for cool. They do seem to hold a little more moisture than poly, but still keep you warm. If you are commuting or riding daily they are not NEAR as stinky as poly. You can easily get a few days use without smell issues.

You do need to be careful washing ... I put a small tear in the short sleeve. But with modern Merino washing on gentle and laying out to dry is really no extra effort.