Yeah, as the block "splits" the water in half that area mentioned appears like it would control the water well, avoiding direct collision and possibly increase flow.
One thing, it's not real easy to tell from the pictures, but there's been a lot of talk regarding turbulence around here, and I'm wondering if there are any measures in this block to increase turbulence.
Other than that, you've certainly got a looker, the dual tops are nice too, options options options!!! Some really nice curves... sexy blocks.... mmmmm
Great work!!!