StevenB,
The only mess is you would be carrying/using an extra item with a Midicable. Both units are identical (have identical functions, main parts... etc) as Leezone describes above. All you loose are 61 keys and mode & bend wheels (which you can use on the Korg).
Yes, you can actually midi both units such that you get ...e.g.
* Styles from Ketron, lead sounds from Korg.
* Styles from Korg (played through AUDYA 4 with Ketron Sounds)
* Styles from Korg (tracks 1 and 2 sounds from Korg, tracks 3-5 sounds from Ketron)
* Styles from KETRON (with endless combinations of RIGHT/LEAD voices)
* Styles from KETRON (tracks 1 and 2 sounds from Ketron, tracks 3-5 sounds from Korg)
Hope this helps.
Thanks,
AJ