Standard old school plunger is pretty much the last vestige of the original pinball games built hundreds of years ago. They are a part of the game you can't replicate.
ONe of the smartest things Stern did was ALWAYS use a manual/auto combo plunger in their games, going back almost 30 years? (except T3 I guess?)
I can't think of any game that was improved by not having a manual plunger.
Some of the novelties like the IJ gun handle are great through.