I think when using of the shelf commercialy availble radios 72 and 2.4 proberly have simlar range in any case they both will allow you to get the model
farther away than you can see it. That being said about 1 to1.5 miles is about the best you could hope for using the standard of the shelf made for
hobby radios. The AMA has a rule that 72mhz flying sites have to be at least 3 miles from each other unless they have a freq sharing agreement.

So think about it if planes can be flown at two sites 3 miles apart with out interfearing with each other that lets you know what you can expect as
far as range although range can vary based on location and terrain.