We used to use them all the time. The Water mice, sprites, and then sea racers used to be so affordable. Captain's Plan was $100 for length of stay. My sis and I would rent a boat daily. It was so popular, you had to sign in and then they would estimate when to come back for an available boat.
The prices are way too high currently. Maybe because we have our own boats here at home, we understand the price gouge.
But something is wrong--for the amount of Guests at Disney Resorts, there should be wayyyy more boat traffic. They even got rid of boat rentals at the Moderates! It's sad. Something is wrong, and I will argue it is the price point. The Resorts and lakes were so much more alive, and kinetic, with the fleet of sprites, bumpers boats, paddle boats, and all boats.