opinions please, on how to break in ....

No, bike cams dont have any break in. They have the cam acting directly on the valves . There is no cam break in. And as an air cooled engine, the rings and pistons wear to fit the bores. So as he says, you run them, shut them down and let them cool. Then run them, get them hotter, and shut them down and let them cool. These are big bore street/race engines. The only thing they have in common with a car engine is they are four stroke and have the same basic parts. My instructions are to take it easy rpm wise for the first 100 miles, limit the idle time, and drive it under load as much as you can. A long hill, or simimlar is great. With the right hone pattern, the rings will be almost seated after the cam break in. The final bit will happen in the first 20-30 miles if it's the right kind of mileage. After that 100 miles, you can up the timing and beat the hell out of it all you want.