Here are a variety (okay, limited) of Spanish virtuosi. The way that they hold their guitar differs, but two players here (Pepe Romero, Narciso Yepes) have visibly different and lower neck angles than the rest.
When I've tried the "Pepe/Yepes" stance, it doesn't work well for me. Yet certainly both of these players are at the top of any reasonable list of virtuoso CG players.
Can someone help explain the benefits of the lower-angled position?