I tried CDs for one day, i reckon i spent half a day just burning CDs to take to a gig for one night. And that was doing 8 tracks per CD. USBs, just keep your itunes up to date, then plug your usbs in, analyse tracks in recordbox and copy across. Much quicker for batch processing, can have playlists, view by artist, album, track, key, even search. USB is the way to go on recordbox compatible players