Hi, I am also a performer that use the T2, and a few weeks ago I sold my PA60 to a friend, well, as a former organist, I feel more comfortable with 2 keyboard arrangers, I am also considering the same boards you mention, I did own Ketron X1, and 2 SD1s, I was very happy with the tome generation, the issue I had with them, in been corrected in the SD5 (128 note polyphony vs. 64 in the previous models), the interface is not as friendly as the Yamaha, but I got to know it well in off, that I did consulting for the collages that use a Ketron product in the Phoenix Az area, also I got to know the Korg since I owned one PA60 for almost 3 years until last month, user interface is also different than the Yamaha.
What kind of styles do you use?....I ask you this because the PA800 has over 300 styles from factory, the SD5 a smaller amount, but I will add that both have great quality styles, it boils down to what do you like better not just in styles also in tone generation, one thing more, I feel a little let down by Ketron since they still include the floppy drive instead of the USB ports, for me, I personally think that adds are more favorable toward the Korg PA 800, I repeat, for me.
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mdorantes