I'd think with the new vocal harmonizer many curent S910 users would want to up-grade.
Less than 50% of my clients buy the higher end arranger for the vocal harmonizer...it's mostly for the sounds and features.
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.