Travis - the main advantage of the Spinoza 13/0 is its size and gape. It's a much bigger hook that the biggest SJ-51 which is a 11/0. It's a very, very similar hook to the SJ-41 and it is made by Owner for Fisherman.
It is really only useable as a single as the eye is to small for bakers - unless you don't use a split ring.