Thanks for all the comments - really helpful.
I should tell you what lead me to asking the question. Earlier this year I had two issues - the image on the screen scrolls, and Stroke of Luck wasn't registering properly. A repair wizard came out, fixed the SOL issue, but wasn't able to repair the screen. He suggested that if I was going to replace the screen to upgrade to color. A few months and probably 500 games go by, and now a shot in the saucer will advance multiball rather than blow up the saucer.
Being a noob, I'm not sure if I'm just coming across an unlucky run of problems, if this is indicative of a bigger issue with the machine, or if I should just expect regular repairs from 20 year old electronics. If it's the latter, I'm inclined to test out a remake. From many of your comments, it's probably one of the former. But knowing the type of issue I'm coming across, maybe you have some specific feedback.
I just want it to work so I can get back to trying to rule the universe.