Hi John,
I have a s910 and use it much the way you are thinking about. It's a powerful instrument in a nice light package. I use it in a 100x200 foot club house with just the keyboard speakers. The styles are very good and there hundreds more that are free on the internet. Setting up pre-sets is not quite as easy as the KN7000 and some of the voices don't come close to the 7K. That is, they don't sound like the real instrument, but it is possible to edit the voices and improve them. Check it out and see if you like it.
Frank