I know you own a Ketron... but amazed you want to play it, if a lack of a GB sized RAM is enough to keep you away from the Audya

You enjoy your current Ketron for what it is, rather than what it could be better at. Why not enjoy the Audya for the same reasons..? It's never going to have everything you want. Nothing ever does. But if it beats your current Ketron by quite a bit, why isn't simply that sufficient? I'm sure you didn't hang around when your current Ketron came out going 'it's only got USB1' (if that), or there's no sampler, etc., etc.. You bought it for what it DID...

Me, I'd quite like an Audya to take for a spin, but I think I'll wait a couple of years and buy one s/h when the price returns to something closer to reality.. In the meantime, I'm just happy I have an arranger where you don't NEED to load up a decent piano in RAM. The onboard one is quite sufficient for me! Plus an extra 64MB SRX ROM tones that is always instantly available makes more sense to me than a sampler you never, in the heat of gigging, have time to load up.

I still think adding a V-Machine or Musebox is the more flexible way of adding sounds, if the arranger's MIDI capabilities are capable of addressing it correctly.