I was in Southampton and Lymington and tried both Ockes hull sold by Mark Pascoe and the Scorpion.
I aimed at the size abowe you, but my experience might help anyway.
First I tried the 8.5 Scorpion with the 2 x 225 Mariner. That was soft and and steady. When we made 42 knots, it was almoast boring, no slamming or seaspray. We saw a ferry close to the needels, went right behind it without pulling back on the throttle. Still soft as could be. We also went beoynd the needles out in the bigger sea, still very stable and soft. At one point Graham even let go of the stearingwheel in 42 knots. That was no problem.
Two days after we went to Mark Pascoes site and tried the Sportrib 9m. with twin 300 Mercury racing engines.
He didnt hold back anything, we went out there doing 78 knots on my pocket gps, we jumped behind a ferry. It was the fastest ride I have ever experienced.
At some point I asked Mark to go 42 knots for a while so we could compaire. In my opinion, the Sportsrib is a bit harder in the sea. But I am sure it will go faster with the same engine as the Scorpion. It is also a more expensive and lighter hull than the Scorpion.
I want the rib for going in huge waves, and on disadvantage is that the tubes and bow is straigt, so it will easier plow into big waves, atleast going with the wave. A friend of mine has a 29 revenger with the same straigth tubes, and it plowes through the waves all the time in 3 m. and bigger waves going with the wave.
So I ordered a Scorpion.
If you want to look at some guys who have made the most out of their 8.5 Scorpion, go to www.actionboat.dk
They have taken the world record from Oslo to Copenhagen, and has a topspeed at 63 knots with 2 x 225 Evinrude. Infact they also have the 7.5m Scorpion. The owner of these ribs has had many ribs also Humber. He was so pleased with his 7.5 that his choise for the next boat was given.
I hope this helped a little bit!