Re: Hydro foils
I've got Stingray hydrofoils on my 16' aluminum Starcraft with 70 hp Johnson and my dad's 16' aluminum Smokercraft with 60 hp Johnson. Both boats have power trim and tilt. In both cases there was a noticable improvement in getting on plane and controlling how much the bow came out of the water coming out of the hole. Also, both can stay on-plane at a lower speed. This is regardless of how you used the power trim. Both cases also didn't notice much change in top end, but then again I never measured it. I would guess less than a couple mph loss, if any, in both cases. Also never experienced any problems like you hear about regarding handling. Both of these boats are V-hull aluminum and we (dad and I), were very pleased with the results.
The Sea Ray in my avatar doesn't have one, and I've been thinking about taking the one off the Starcraft to try it. I've been thinking about going with smart tabs on that one as well to help with the lean under power though. I need to research how they would have to be installed on the back of the boat since the stern is curved and isn't straight across on that one.
Edit: I forgot to mention that in the case of my Starcraft, the foil also has the optional fins that you can bolt to it and they are set to virtually eliminate steering torque.