You know one of the things that interests me most about the Tyros is the lighted panel buttons. I'm working in a very dark environment right now and must use portable lights to see the buttons.
I also think I could really utilize the versatility of the outboard speaker package.
I love the Yamaha OS and really dread having to learn the Ketron, plus deal with the awkward (to me) placement of the fill, variation and ending buttons.
If it sounds anywhere near the "live" sound of the XD and SD1, they may have a winner.
But we are still being really premature. The thing is not yet finished, so nobody in the world can really give an informed opinion of the finished package. Yamaha is famous for adding great new features but taking away something great that was already there.
Don