If you think about it. Technology on an engine driven fan was limited. there are issues with the Mercedes 107 SL. There is a difference to be noted with the older fans incorporated back in the "day". Now they use a durable plastic fan. Lightweight and scale free.
For People like myself who want to keep "this car of mine as original as possible" I will keep that aluminum fan. I was really tempted to switch over to the electric fan based with a controller and decided against it.
I Don't need to spend the money on a "puller fan" plus the controller.
There are problems associated with keeping the engine cool especially when you are located in temperate areas.
The least amount of turbulance the fan produces the better you will be. Remember that the air is directed over and around the engine as well as cooling the engine itself.