Great post. I prefer older design as well. I own a 70's El-primero and it's my favorite. Zenith has been making good and solid chrono since El-primero is invented. The older ones (before2000) are really value for money consider other lesser brands cost more.
However, i am a bit disappointed with service from the factory. I had sent in my 70's El-primero for glass replacement late last june, was promised that it would take abt 1 to 2 mths time but only managed to get it done last last Dec. Last week i have to send it back to Singapore service centre for testing coz the glass wasnt properly sealed, water has gone it (can see vapo inside the watch). I hope it will not ruin the dial especially the illumination parts as i bought the new original dial from the factory only a few years back. Hope i can get my watch back next week.