This is a thin lightweight base layer, but since it is Merino wool is feels warmer than the weight would indicate. Fit is pretty snug, as it should be, and the longer back is nice for riding. Sleeves are nice and long. The hood is the same thin Merino and fits fairly close to the face.
Great under a thermal jersey as a single base layer for the low-40's and under, but the hood has a narrower temperature range. At 45deg or above it's simply too warm to wear a hood, and at 35deg or lower the hood isn't thick enough to provide real warmth. Under 35deg you could wear a hat over the top of the hood and still get awesome neck protection, but the hood won't be warm enough on its own.
I've found the best time to use this is on rides that start in the 30s and warm up from there. Once it warms I can just pull the hood down and I don't need to worry about stuffing a hat in my pocket.
Overall this is a decent (but not awesome) piece that should see a moderate amount of use road riding in northern New England winter.