In my experience on my P20 Choppers tend to be surface piercing props with quite a bit of bow lift, you will struggle to hang onto the boat if you are running twin ride glide due to the torque, also have a tendancy to try and turn the boat over if you back off violently. Shouldn't need a lifter though but to get the best out of it you will need to be running no more than about 1" below.
Thanks Burty, I'm using hydraulic steering so the torque steer shouldn't be a problem, but I'd like to stay the right way up . I suppose the only way to see how they perfom is to try one.