I have had iTunes Match on my iPhone for some time and previously didn't have genius. In the past the only way for me to listen to songs would be to press the download from the cloud button and listen while downloading. Recently I updated to 5.1 and noticed Genius is accessible on the iPhone. When I press the genius mixes it starts playing songs but does not show that the songs are actually downloading. Are they streaming? In short, I have a small GB iPhone will listening to genius mixes on it fill it up with downloaded audio files causeing me to have to find and delete them more frequently?