THis post prompted me to check out my new CVP805 to see what files had been included in the sale.
I don't think it matters, which memory is used for storing Styles or Registrations, there is no technical limitation, other than the User Memory is only 2GB, compared with the much larger USB sticks, however 2GB is still capable of storing 1000s of files.
Currently, my User Memory contains around 1700 preloaded Registrations and a few of my own favourite Styles.
The USB slot under the keyboard houses a USB stick supplied by my dealer with a further 1600 Registrations and a copy of what I believe to be the latest CVP805 firmware.
The front USB slot houses my own USB stick containing 1000s of Style files, downloaded from this forum.
In my case the CVP805 was purchased as an upgrade from my previous CVP605, so the panel layout and operation is virtually identical, but senior moments do happen