Have spent the last three days solid on the new SD7 getting it ready for next weeks Keyboard Cavalcade event at Blackpool.
For example, on the Audya it was possible to assign different sounds to each arranger part (like Tyros), but the process for setup is greatly simplified n the SD7 as you can touch and hold an icon to select a new sound. If you use registrations, which I think you will want to, the things you can do are incredible and seemingly endless.
For example I am setting up registrations so that when selected, the full sheet music (two pages) is displayed on an external monitor so no need for page turning, 4 sounds are preselected for upper, the lower voices have been tweaked and both upper and lower voices change with each arranger part...and then saved all in a registration. It takes minutes to do all of this due to the intuitive touch screen based OS.