My buddy has a 150 HO on his 19 Duckwater, it does 46 loaded. Raced some guys from the ramp one morning to a spot on the bay. They took off and left us in the dust, until my buddy put the hammer down. Talk about scaring the hell out of ya. That's pretty fast anywhere, but in the dark on the bay in December, WOW. We did have a go light.
Enjoy your boat, I love mine. I have a 115 etec on mine, I can do 36 with 2 of us in the boat. It's a 17.5 footer Duckwater, all aluminum w/ a 9.9 kicker.
Just a note, I don't know if you've ever had a jackplate before of not, but be careful when you running on plane, if motor is too high it will be starved for water and over heat. Thankfully someone mentioned it to me, I never would of thought about it being an issue without having owned a boat with a jackplate before.