The problem with the IR system was the necessity to encode the signal so that sunlight wouldn't interfere and then the line of sight problem. And where to put the receiver? A fighter can be shot down from any angle as long as the shooter aims at the airframe. The other problem was complexity and expense.
Parts for the RF system are under $10 per unit. The circuit runs happily off 4-6 volts so power will come off any unused receiver output normally used for a servo.
The Mig 15 and Sabre are coming along but I failed to order a receiver that would work. I'll probably have a garage sale soon of leftover un-needed parts. The Spektrum receivers only work with certain transmitters (Duh). The 12A ESC I bought were way overkill and heavy. So now I wait on new components to test the Mig and Sabre.
There is a real market niche for a company to sell matched component systems. It's a jungle out there trying to get the right parts.
This is a wonderful hobby to learn about all sorts of sciences. And, yes we learn best by doing, making mistakes and studying the successes of others.