At A Glance Pro - Good strap buckle. Con - Some restriction to field of view. Volume -140 cc. This reduces bulk and gives good nose access, but restricts downward vision. It is 45 degrees at that point, less elsewhere.
Volume is low and the standard-sized strap adjusts easily in swiveling buckles.
At A Glance Pros - Good field of view, good nose access. Con - Field of view somewhat restricted. Volume - 140 cc. Volume is quite low. Buckles swivel and are mounted inside the frame in such a way that nothing protrudes to catch line or seaweed.