BTW, I'm curious as to why some have no fills... how the fills connect the different Variations, how it all flows together is as important as the basic sound.

And particularly with audio styles, there's lots of opportunity for one audio file to not transition smoothly to the next one (whether it's the recording, or the hardware's fault). For one thing, how do you get crashes on the 'one'? Are they always MIDI crashes on the very last tick of the fill (like MIDI styles do), or is there a way for the tail end of the fill to ring on, while the audio engine plays the beginning of the next audio file at the same time?