Hi MoonKS,
There are 2 basic ideas concerning break-in. The latest offering suggests "harsh" treatment, such as WOT going up a hill , all in the first 20 miles. The latest concept suggests the rings will seat much quicker, and seal the cylinder & rings quicker. In the past I have been forced to use the "harsh" method on a re-built motor during my racing career [complete over haul in my Motel room] because I trashed a motor and didn't have time to break-in prior to the race. Every time I did it that way I always had to re-do the motor, and usually replaced a lot of parts in the process.
The only time [in my opinion] the severe brake in proceedure will work is if the motor has excessive clearance between the piston & cylinder. Just to make sure I wasn't closed minded to a new concept, I recently broke-in a new Whizzer cylinder using the "harsh" method, but after I removed the cylinder to take a look I found the piston "gaulded" on the front bottom of the skirt, and the area just below the oil ring on the back side of the piston. The wrist pin was a deep blue [over heated], and the rings were "scraped" badly. It was an expensive lesson , good thing I am a dealer and was able to replace the parts at dealer cost. Another area I found interesting was the comments about the rings seating, but in fact it is the cylinder that makes the biggest adjustment during break-in. The cylinder is "cross' honed, and it is the raised areas of the cylinder that wears quickly, not the rings.
I always break-in my motors, easy and once in a while [after 50 miles] I will open the throttle completely for approx 1 minuite, then drop back to allow the motor to cool down. I have found it very important to vary the speeds during break-in as opposed to holding a constant speed.
While it is true the "harsh" method will reduce the blow-by sooner, it will also allow blow-by to return in a major way later in the motors life. I have several motors with over 6000 miles each and these motors [after normal break-in], and these same motors hold several speed records above 68 MPH on the Dyno.
You be the judge!, but I will continue to use the "old" method, because "why fix it if it ain't broke".
Have fun,
Quenton