As a life long Audiophile IMHO:

The Tyros displays the most openess and spacial positioning. The sound stage expands with each instrument placed in proper perspective.

The G70 is a close 2nd. I always thought Roland had a big open sound.

Audya is third, more narrow soundstage, although it may have the best drums.

Korg is last. It has a narrow soundstage with no dimensionality and a more closed somewhat compressed sound.
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joesax
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https://music4stressedoutsouls.bandcamp.com/
Tyros 3, Motif XF6, Quad Amp/Pre-Amp/DAC, Quad Monitors, Tascam Digital Recorder