(Matthew's wife here) I used the size chart and bought a size large because of the bust measurement.  It's plenty big around, but if the seam is supposed to sit under the bust like it does in all of the pictures of the models then it definitely doesn't have enough fabric vertically for women with bigger chests.  The seam goes straight across my bust which looks a little awkward maybe.  I love having lons sleeves so I don't have to worry about sun damage to my skin and the cinching bottom-half makes it easy to adjust to a long or short torso (mine's long)