There's a lot of contention regarding engine break-in period. The consensus I've seen amoungst persons who tend to have more technical insight is: slow and low is a holdover from older engine technology. There are some really good articles you can read associated with dyno break-in that will get into the details. Sorry, on phone, so no links. But, basically, the main point of break-in is to seat the piston rings.
There are three factors which significantly impact this: temperature, back-pressure, and cylinder/sleeve wear. You don't necessarily have to keep the RPMs low, but you must prevent the engine from experiencing very high temps for long duration. When revving the engine, you must allow the revs to drop under load (engine breaking) to maintain high back-pressure. And the break-in period is most critical in the first 20 or so miles, after this, very little additional wear occurs because of the extremely close tolerances and hardness of modern alloys. After that, you're good to let her rip (minding tire break-in). I've found some very detailed instructions on break-in, they're not too difficult to find.
Controversial topic, so I'd recommend doing your own research and making an informed choice. I talked to the a tech at the dealer about taking her to a dyno shop for break-in, his response "just rip out of here like you stole it, better yet, like you just bought a crotch rocket, that's about all the break-in that engine needs."
Last edited by USSENTERNCC1701E; 04-27-2016 at 08:02 PM.