correct....Had one of those nozzles on my old square nose. I loved it compared to the stock nozzle. I think that center divider helps quite a bit. Acts more like a rudder applying more surface area to the jet steam. Wish I still had mine.
I too noticed a good difference when I had switched op nozzle on my old 650 SJ. Mainly in turning or carving whatever you like to call it.
When it comes to running bigger CC motors and aftermarket hulls. It would be a waste of time IMO.