I've got a 15hp pro kicker, over kill for my application, 19' runabout with sterndrive. It was a derby prize.
Before this I had a '78 evinrude 9.9 2stroke. The 9.9 worked fine in calm conditions but didn't have the traction on windy and rough days, it was mainly used as an emergency motor and mostly trolled on the main.
I can troll in heavy current, wind and bad water no problem with the 15hp and only start the main if waves are coming over the windshield. Love the motor but wish it was a 9.9 pro kicker, for the weight savings only.
My boat get to hull speed slightly past 1/2 throttle, just makes more noise after that. I think boats 24'+ would utilize the 15hp to get hull speed.
Also not sure how you would steer your kicker but the TR1 gold has trouble steering my kicker at hull speed, not enough torque to move the motor from side to side at higher throttle, this would be amplified with a bigger boat.
I've got a 2010 extra long shaft, power tilt, remote throttle 15hp pro kicker.