I agree that it's the player's 'competency level' that can make a big difference,
but put the 'same' arranger keyboardist on each one of the different arrangers (G70, Audya, Tyros 4)
and I think you'll hear the 'strengths/weakness' of each given arranger,
including its 'versatility' to impressively cover a broad range of musical genres.
This is where I believe the Tyros 4 shines.