Factory settings (or harder) is the way to go!
Also the "i will pay for a better score" (= extra ball buy-in, e.g. on STTNG) feature is always turned off on my machines as this feature is purely a money-maker for machines on route and makes no sense at all in a home (free play) environment.
In general i think setting a modern game to 5 balls is the same as changing the game settings to "easy", so in the end it's kinda like cheating...