I can only speak from my own experience, (but as the applause from the 1500 or so audience after Brett had performed, was more complete and intense then either the G70 or Tyros 2, then they must have had similar thoughts) but I found that while the Tyros 2 and G70 had good points, they also had bad points, were as the Korg was just evenly balanced. (Like a good set of musicians that have been playing together for years, and so had that real polished feel)
Like most professional performers Brett use's both sequences and wave files to get the sound and authenticity of certain types of music, but plays live as much as possible. (While playing the Korg he did say that he wasn’t quite sure what to do with his feet, as the Wersi Scala he plays is a full organ and so his feet would normally be in control of the expression pedal, and also playing the bass lines of the music, plus his hands have 122 Keys to play with)
If you require further details have full read of my Caister Review.

Bill