Well, this is purely a matter of taste.

I played new Ketron board for a couple of hours, and my impression is that its voices are a little closed and plastic.

Situation will get better using an external amplifier, but still not as good as other arrangers.

Following my tastes, KORG PA voices are still near the top, with Roland voices very close. To me, Yamaha is a little lower, but I never listen to the new TYROS. And I never listen to the GEM GENESYS too.