Bill, you're right, you don't have to, but it's still very convenient to me to have all the styles I use in factory locations.
I like the Ketron registration system, so I used it almost exclusively. Don't like Yamaha's registration system much, because you can't just save a single registration, you have to deal with banks. Pretty much the same with Korg. Better with Roland.
On my Yamaha, I have so many styles, I need to spend about a week organizing them!
Thanks,
Don