I have only played one EM and it is the Super Flite I own. I got it in pretty rough condition and cleaned it up and fixed all the little mechanical issues on it to get it playing. I didn't think I would find it very enjoyable, but it was free, so I figured no loss if it wasn't much fun. As it turned out I love it. The sounds of the chimes and coils and relays are pleasing to me in a much different way than SS machine sounds. They are more visceral and industrial. Gameplay is simple, yes, but sometimes I find that a nice break from a complex rule set. Another attraction for me is, being a maintenance tech by trade, working on them is extremely entertaining. The fact that somebody could design a machine to do what it does through such a complex setup of switches, steppers, relays and hundreds of feet of wiring is awe-inspiring to me. And when I trace out a problem in that maze and fix it, it is a rush for me.
So, that's why I am a fan of EM's.