The chance of going wrong with a floppy is very big.
USB-stick forum way has proven to be the best and stable way, so far not a single board has gone wrong.
Sure the attempt failed a couple of times, but that was due to the stick, however it didn't ruin anybodies BIOS.
(Fixed by using a tool to prepare the stick, we will include preparation in future versions)
The only way the USB method can fail is when MSI makes a mistake in the files they present.
Our method can't go wrong, too many checks build in, even a bad download won't let you flash.
To go wrong with a floppy is simple, 1 bad sector can be enough to flash bad, has happened to many people already.