There is always the talk to improve engine performance by lowering the intake air temperature. Cold air intakes apparently being the most effective way to achieve that.
I do get the concept as the temperature difference between under hood and ambient air can be quite significant but how big is the difference while driving - especially on a 68-70 B-body? Since the engine compartment isn't sealed there should be constant air exchange. Most of the incoming air has to pass through the radiator and will be heated up but by how much?

any real world experiences? Is it even worth it to make up my mind about a cold air intake for my 70 Charger?

One advantage might be the location of the cold air intake opening - if placed in a high pressure zone.