The issue with the KORG (Italian made) Pa FILL INs is thus (in my opinion).

If you press the FILL at the right time (down-beat), you get (for many styles) a slight increase in volume especially on chords that have/use guitar tracks.

If you press the FILL at the wrong time (up beat), you get both the increase in volume AND feeling (hard to put into words) that the fill is trying to "CATCH UP" with the variation you came from ~ almost as if the FILLS and Variations/Endings were programmed by different people. This issue dates back to the entire PA line; but WASN'T the case with the (Japanese built) "I-series"!!

When I asked the Korg Italy S.p.a Engineer at NAMM 2007, I was told the intention was to emulate the 'excitment' a band portrayed when they played a fill/roll - however (to me) they do not sound natural!!

Just my thoughts ... but the variations are some of the best out there with the 'subtle' variation within the style variation technic - especially within styles with long measured variations.

Yamaha, Ketron, Roland and even Technics have smooth style transitions and no matter when you press the FILL, you get a smooth fill and return to variation!!

AJ