For one on my toon the front spash gaurds on front of the tubes are reinforced and completely boxed underneath them, I think they add a couple extra gussets to the frame in other areas too but not sure where exactly. The package was cheap when ordering I think it was only 200 bucks or close to that.
I attached the best pic I could find where you can see the boxed splash gaurds on my boat. The Pic was taken at Aquapalooza at Fort Stevenson state park on Lake Sakakawea near Garrison North Dakota this last summer.