One advantage of EMs that I don't think anyone's mentioned here is that the playfields are usually much more open than on newer machines. Modern games often have so many ramps, bash toys, scoops, mini playfields etc that the area you have to hit the ball around is actually quite small (some games, like Taxi or Playboy, feel downright claustrophobic). You end up spending most of your time negotiating obstacles, and your shots feel like they've been dictated by the game designer. Whereas the open playfields on EMs just seem to allow the player more freedom to use their own approach to the game, largely due to having more potential angles for hitting to the upper playfield.