The harmoniser has never really been a feature I ever used as I sing and play for choirs and small groups anyway . There are very few shops near me that stock the korg pa4x and none that stock the pa3x . I did play the 4x once in a noisy shop . It sounded ok but the key feel was definitely more stiff and springy than my pa1x . Felt weird .

Really could not hear the quality of the sound . Other than the vh , what do you prefer in the 4x over the 3x ?