The lower the better, less wear on the gears during shifts. I idle at 450rpms. That would be too low an RPM for someone that likes to troll, but I mainly ski and cruise, so it doesn't worry me.
Well, I rented a 2003 17' Sea Ray with the 3.0, and with 4 people onboard we could only manage about 32mph. The sucker wouldn't plane until two of us sat in the bow...<br /><br />But hey, it got great gas mileage!