Agree that the factory method is the 'toothpick' method and it applies for the vast majority of machines but I have had one or two machines where I wasn't happy with this setting and personally, and I stress personally, I found the machine played nicer using the straight edge method.  In the end it comes down to personal preference as well as the strength and efficiency of the flippers on that particular machine.  Trial and error until you find the sweet spot for your machine.