I haven't tried a Korg arranger yet, but I can't imagine that all styles would be "awful".
If you are not into style programming/editing then the Yamaha styles seem to be best out of the box.
If you like to modify the instrument to suit yourself, I see no reason why the Korg could not be made to work well for each individual's tastes and needs.
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.