I've used fedup on 4 very different machines, and it has worked faultlessly.
Thanks for reporting. I was afraid of upgrading (F18->F19) and would have waited months. After your message, I did it and it worked perfectly well: 1. I downloaded the DVD iso: Fedora-19-x86_64-DVD.iso 2. fedup --iso Fedora-19-x86_64-DVD.iso --network 19 --reboot It took 42 minutes before automatically rebooting. The total upgrade duration was 2 hours. This leaves 1h18 for installation. I launched that before going to bed. In the morning, everything worked perfectly apart that the default session type was changed from KDE to gnome.
Thanks to the fedora team,
Frédéric