I'm having a hard time with this; not sure what to think. The people who say that "anything that doesn't result in a tilt is not cheating" are not looking at this objectively in my opinion. By that logic, shoplifting is not shoplifting if you don't get caught. Seems to me it's still shoplifting. There can only be so many mechanical checks in place to ensure that cheating is not happening but if there is not a mechanic that can detect that the machine has smoothly slid an inch or two, that does not mean that it's not cheating and the designers of the games would condone it as a legitimate strategy. Personally, I'll do a slap save but I don't believe that physically moving the game during play is something that any pin designer would consider as legitimate, if it's detected or not.
I do love pinball either way!