I've tried other u-necks that left me very strangled and/or hung up under my arms. hmmmm. That angled line from under the arm to somewhere on the chest is not easily corrected if it does not work just right with the neck and back.
So far I've made this pattern in a muted lime green and in a dusty rose, both medium weight rayon/linen blends. The drape is really key, so I wanted to stay away from anything stiff. Not for knits unless you plan to use a camisole or strapless bra.