Advantages of flashing radios?

[Sim-X]

So I was looking through the radio thread and see there is 6 to choose from. There really isn't any information on what exactly the advantages are for flashing the radio and which one to pick or if I even need to. I haven't done any kind of radio flashing yet just because I don't know a whole lot about it or couldn't really find any information about it as far as what it is actually doing.