"This is the cotton sweater I've been searching for." People say it more than anything else, and the search is the point: you wanted a real sweater — a shape, a rib — light enough for the months when a sweater is usually too much.
Cut easy through the body. The side slits are what people mention — the hem sits open over jeans or white trousers, and drops a little at the back. Light enough for a Southern California afternoon, and still a sweater when the evening comes.
Spring on its own. Summer after the sun goes. Fall over a shirt, winter under the coat, and the weeks in between that can't decide. It comes in solids and in stripes — and when the fit is right, the next one follows.