Been following the SuckGate thread and built two versions recently similar to bet_on_black's posts. I first used the Seastow cups (center one) but it kept coming off. The aluminum cups (right one) worked well. I placed both versions with the fin nearest the back of the boat. When I loaded all my ballast (700 in each Vdrive locker; 350 internal on each side and 400 in walkway in bow), I had difficulty holding speed at 10.5 mph without pushing the engine to 4200 rpm's. So I emptied my internal ballast and reduced my Vdrive ballast to 1/2 levels and was able to hold speed at 3700 rpm's.
All my riders thought the surf wave was longer with still enough push versus our old method of listing the boat to one side (700 Vdrive, 350 internal and 400 in walkway).
Still want the Seastow to work, so next time out I'll look to relocate it and see if it sticks.