OnAir2 is very solid when it comes to the radio player ! Easy to setup and very efficient. The radio related pre-coded pages like shows, charts, podcasts are also very well integrated an everything works perfectly !
On the other hand, OnAir2 is probably the worst theme I have seen in its price range when it comes to customization. If your website won't look exactly like the demo, you will need some serious website coding skills. The whole website customization is limited to a couple check boxes and a very basic menu... Very frustrating.
Add real customization features to OnAir2 and it will be the killer Radio Theme !