"The USB option is useful if you do not wish to disturb your rig in order to gain access to the memory cards."
"For uploading via USB, turn-on your camera, in Scripting menu uncheck 'Disable USB Download' and switch to playback mode.
If you are using a dual-partition card, use SDM menu option Debug\Swap partitions before proceeding.
Remember to swap again (using the SDM installer) to restore camera to normal SDM booting.
Alternatively, just unlock your card and startup in playback mode."
Other than single partition cards, it's not worth it