I'm on the side of Motoman. He knows what he's talking about. And he's right. I've personally seen the evidence via compression tests. Let's break my discussion into 2 parts.
Part 1: If the hard break in method works so well, why are manufacturers telling everyone to break in their bikes easy? The answer is they have ulterior motives driven by their lawyers. They want new riders on new bikes riding slower and taking it easy so they don't kill themselves.
Part 2: You get better compression if you break it in hard. I've seen it first hand. And even before I tested any bikes compression I saw it on one particular forum with one particular bike: The KLR650. Some had a tendency to burn oil, particularly the 2008-2009 vintage. Some didn't. And THE difference was how it was broken in. If the bike was babied, you ended up with a lower hp oil burner, guaranteed! If you properly thrashed it, you ended up with well seated piston rings, great compression and no oil usage.
Answers in this thread should be restricted to people who have compression testing kits and have used them on new bikes, many times, before and after different types of break in. Anyone else is flying blind.
The best break in is at the race track. Just be sure to drop the oil after 20 laps, then again after another 50 or so.