Revisiting iTunes/iOS sync issues | The Robservatory: "incomplete syncs due to bad disk sectors in just a couple of songs (apparently when it hit the bad sectors it quit entirely–and silently–rather than moving on to the next song)"
My theory is that there have always been bugs and problems with iTunes sync, but when an error occurred iTunes moved to the next operation. It didn’t quit or hang. It also didn’t log anything useful to Console.
Now iTunes still doesn’t log anything useful to Console, but it doesn’t continue. It just quits the sync operation (might move to next one).
I hate you Apple.