EMs can be really fun when set up and maintained correctly. At some of the shows I've been to it looked like the EM games present were just put there to have a game there, but no-one bothered to level them. Obviously that's no fun to play.
I've played some restored EMs and was amazed by how fast they were. Love the random ball movement and the fact that they look easy to play and turn out difficult to master. Just shoot all 12 switches on the playfield to light the corresponding number and I end up trying again and again.
Last year I discovered the Gottlieb EMs when visiting PHOF in Vegas. Prior to that I was more familiar with Bally and Williams EM games. Played away $30 in quarters in one afternoon and had a blast Also played mostly EMs at the NW show and CAX last year.
The fact that technology wasn't that advanced, compared to modern day games, is something that I like. The game had to appeal right from the start. Plus that these games were pretty complex with all the relais, score motors and such, but that's more under the hood complexity.