After updating 3 iDevices in my family, and two for different neighbors, I will expand on the formula that seems to have worked for me. Every single iDevice I have upgraded has encountered one of three different 'hangs'. Note: I do not use Genius, nor have I ever had voice memos, so those remedies were not relvant to me.
- Update only ONE iDevice at a time, turning OFF all other iDevices.
- Make sure to update iTuunes.
- Plug in iDevice via USB, but click out of the offer to upgrade.
- Transfer purchases and then do a backup
- Now select upgrade and follow along.
- If and when you get to the hang', click out of the progress bar to end the sync
- Now 'eject' your device, unplug it and turn it off.
- Reboot your computer and restart iTunes.
- Turn on your iDevice and Look in your device 'settings' to see if in fact you now have ios5. If so, disable iCloud and disable "sync over wifi"
- Reattach your iDevice, and go right to Info and Summary - choose "Backup to computer" and choose "Sync to the computer"
- Now sync. Hopefully, it will go off without a hitch now.
- IF the sync is successful now, you can enable iCloud and your preference for syncing
- Eject and Disconnect device from computer, and enable iCloud and your preference for syncing
GOOD LUCK - all I can say is, these steps have worked for me