Nice article, I appreciate the information. I have been running an electric fan in my 73 Mustang for around 10 years myself and for many reasons it's one of my favorite upgrades. In my 73 space isn’t a real issue so I have always looked for the best CFM’s and biggest diameter I can get.
Here is some information I would add.
Since I built the motor that is in the car now I’ve only used an electric fan and at first had some overheating issues especially running the AC in the summer. I believe that was not the fault of the electric fan but due to the performance upgrades in the motor, thinner cylinder walls, and the headers adding heat to the engine compartment. At that time I was running a perma-cool rated at 2900 cfm with no built in shroud so I put my fan shroud back on and in my case it actually ran hotter I believe this was because the shroud restricted air flow more and didn't fit the fan the way the shroud was originally engineered to fit around the factory fan. The overheating was solved with a high flow water pump and high flow thermostat, smaller trans cooler to minimize restrictions, and adding an overflow tank. Also in the summer time running a mix of 20% antifreeze and 70% distilled water with a bottle of water wetter lower the temp a bit but a couple of summers after installing the HP water pump I found running a 50/50 mix in the summer worked fine.
I installed a Thermostatic fan control switch that turned the fan on when needed and off when not needed thus saving electricity and putting less strain on the charging system. Also if you think about it if you’re traveling at a speed that is moving air faster than the fan does the fan is just causing a restriction. Some may choose to hook the switch to a keyed power source but I opted to hook it to constant power straight off the battery that way it got plenty of juice and when I turned the car off it would continue to run until the radiator had cooled down. If I was overheating I would have a supply of cool water quickly. If you use this switch with a car that has AC it's mandatory to add a relay to make sure the fan runs constantly to keep air moving through the condenser when the ac is on otherwise you'll build too much pressure when you’re stopped and damage the AC system. I bought the whole setup at the local discount parts store chain and it was cheap and very easy to install. I think I’ve had to replace it due to failure once in the 10 years.
I did end up with a dead battery a couple of times so I replaced the stock 45 amp alternator with a 105amp and never had that problem again. I may have also bought a new battery then but I can’t remember for sure. But when you start adding modern electronics like a new stereo, electronic ignition and such that should be considered anyway.
The one drawback I have found is that after market fans doesn’t seem to last more than a couple of years. I don’t even know how many fans I’ve been through in the past 10 years. I’ve used supposedly top quality fans like perma-cool, flex-a-light, and derale and cheap $50 new fans bought at swap meets but can’t seem to get more than 2 or 3 years out of them. I will say I do drive my car a lot in the summer but I still expect more than I have gotten. I think my next fan will be a factory Mark VIII fan as discussed elsewhere on this site. Maybe the factory fan will do a little better.