I have a question here, Bowen. Do you ever find yourself getting bored playing with other people who are nowhere near your skill level? Or, to phrase the question differently, do you find it more enjoyable to play with people who can seriously challenge you, say Cayle or Keith?
Personally, I find it not that interesting when I'm playing with a newbie who, say, still double-flips. And I sort of feel bad when I end up playing each ball for five minutes when theirs is gone after 20 seconds. It makes me want to play with someone closer to my skill level simply because I don't like to hog the game or make someone else feel inadequate. (When people who don't normally play pinball come to my home, I usually play only a single game so they can see what sort of things can happen on the machine, but then bow out, so they don't have to stand around endlessly watching me play, and I invite them to play on their own.)
On the other hand, if the person is interested in learning something, I find that I enjoy watching them play and then showing them one or two things that I believe would improve their game the most.