Hi Danny,
I currently use a Ketron SD40 module. I previously owned 2 of the SD7 keyboards and loved them. You asked about the USER-STYLES but I want to tell you a key thing to do with the USER-VOICES to avoid a lot of trouble down the road.

Within the USER-VOICE folder put a number, starting with 01, in front of every user voice.
The SD7 OS looks for user voices used in styles according to the position they hold within the folder- they are not saved within the style itself.

I have many self made USER-STYLE folders I created. You go to disk edit and add them. Or you can connect to a computer and add them.

Good luck with the SD7. It is an awesome keyboard.

Deane