Hi guitpic1,

Ketron SD90 module is nice - it allows you to use your preferred keyboards, including the ones with 88-key hammer action.

There are 2 issues that you have to deal with when using SD90:

1. Not all keyboards with MIDI work well with SD90. I found the Casio Privia PX560 works best with the SD90 without MIDI timing or slippage issues. I have MIDI timing / slippage issues with Yamaha S90 and a brand new Kronos 2 88-key with SD90, with the same known good working MIDI cable.

2. The availability of good Ketron arranger styles is rare compared to Yamaha arranger styles.

You have to make sure that you do not forgot to bring a MIDI cable to your gigs.

Thanks,
Paul