Every 100 hrs between 3,400 - 4,250 rpm, which is not that narrow of a band, especially since in my experience that is where most higher HP motors like to run for optimal cruise efficiency. I would be replacing at least once, maybe twice a year. And all great that Yamaha will do it for free, but that wouldn’t do me any good if I’m in the middle of a trip to WCVI or Central Coast and there is no Yamaha dealer around.
For some people the motors might be great, but a hard pass for me. Especially since Yamaha discontinued the motors - which says a lot right there.