So Medeli is a generic manufacturer who markets under its own name as well as others via license or other agreement. Is it possible that they manufactured the SX700/900 for Yamaha rather than copied it? Maybe under agreement that they perhaps use an older sound chip, and/or hold off marketing under their own name until Yamaha reaped the introductory sales at double the price ($800-$1000 vs $2000)? I don't know how it works but I am curious..