You should trust this method. I've always broken in my engines like that. Doing this will make your engine run longer and stronger and yes Daso, this applies to any 4 cycle engine.
Ask any race engine builder how he breaks in an engine and you'll see. Just read the article, the guy knows what he's talking about and I've been doing this for years even though I've only known about this site for about a year. If you know anything about mechanics etc... you will understand it. Anyways, it's your bike, if you want a slow bike, break it in the way the manual says. From my experience, I've never had problems doing it the way Motoman says it should be done. I have 3 friends that race bikes and that's how they break in their race engines and I've talked to several engine builders (for car engines and bike engines) and they all do it like that to.