You can play flac and SHNs on WINamp. You need a special patch for WINamp to play SHN. But the newest version of WINamp plays .flac.
Theres all kinds of programs that convert them to .wav files
File sizes are a larger. but not significantly.
High quality isn't really needed for Radio, but some of us take pride in our music collection.
And aren't retarded enough to listen to the radio.