I save *everything* to the USB. Registrations, styles, etc. But I'm in an unusual situation: I have to demo many different models (at different stores, no less!). When I used built in styles, often a newer keyboard no longer contained even a version of the same style. I used to put things in user, but again, I have then figure out which styles I need to copy into user for a particular registration (my PotC video? I use 4 different styles throughout, 2 of which I wrote and 2 are internal... which I read off USB in case the style is ever omitted in future keyboards)
Like I said, I'm in an unusual position: how many people need to demo the same demo on dozens of different models? Including future ones?
And yes, I make backups. I lost my USB stick for a few days once (it ended up being underneath one of our warehouse shelves, coworker found it) and hadn't backed up for a few months, and I was in an absolute panic. If I'd *never* backed it up, I would've fainted.
Mark