My advice to anyone wanting to buy an S900 would be to either wait and see what happens in the next couple of months or save your money and buy a Tyros.
It might very well be that the first batch had some issues.
But if that is not the case , then keep what you have.
Further reports about the S900 for bound to surface , be they good or bad.
So holding off on the S900 at this point might be the safe thing to do.
Gary