My boat was very similar to yours, a 20' Spectra. And I had the hand throttle as well with a Msd6AL. Personally, with how heavy the boat is, and how well it chops the water with the sharp entry, I NEVER had the bitch come out of the water.
But then again, I didn't really play on lakes like Havasu or Lake Mochoppy either.
For the lighter boats it sure is a good idea, for example at the races the boats are comming out of the water all the time, and zinging V8 motors is probably not a good idea..... even if it is a mighty Mopar

I know you've obviously driven your boat before, but I think the foot throttle makes a huge difference. It is difficult enough to steer these things with one hand, working the throttle with the other(jets only) and trying to get it to turn
Where you want it, and
When you want it to turn. I think the foot throttle is a much cheaper conversion, and gives more control. The throttle/forward control is just a PITA to me in that size of boat.
Just my 0.02