Michaelwrote a review of Castelli Flanders Wind Long Sleeve Base Layer on November 4, 2015
Familiarity: I've used it several times
I love the windstopping base layers. Previously, I've been a fan of the Craft shirts (which are way awesome), but the flanders shirt is every bit as good and even has a few things that set it apart. First, the pits are very well vented. Second, the it's not as warm as the WS Zero, which is a real blessing if you want to go hard and not get sopping wet.
As far as fit, others are correct. The neck is very narrow and can be hard to get over your head. Once on its nice and snug.