Tried to download several times. It downloads for about 7 minutes before an error message appears.
Try it at the time of late night the wifi works faster it will download at this time
Try via iTunes in the Mac, instead from the iPhone direct.
When the iPhone is jailbroken it will not succeed.
Seriously, you might want to check out the wifi issue and sound issue threads since iOS 6 was released. If iOS 5 is working fine for you, I wouldn't upgrade until Apple releases 6.1.
Retrieving data ...