I am a dealer in Calfornia for both the Yamaha and Ketron line. For Styles, the Ketron SD1 has much better and more realistic sounding styles, especially in the Latin area. The reason for this is Ketron uses real audio loops as well as drum patterns and Yamaha only uses Drum Patterns. When it comes to natual sounding guitar strums and picking, the Ketron is much more realistic. Where the Yamaha excels is in ease of use and button layout, although the SD1 is right there with it except for perhaps the physical size of the buttons and the way Yamaha uses it's function buttons different than Ketron. I really like both keyboards, but to my ear, the Ketron SD1 has the edge in performance.
George Kaye
Kaye's Music Scene
Reseda, California
818-881-5566