Many users of other brands may disagree, but I think the Korg "issue" with fill-ins is a matter of timing your button presses. I never hear the glitches, unless I'm sloppy with my presses. Korg is a bit less forgiving with "in between beats" button pushing, but after using one for an extended period, I almost never have a problem with it. My success rate is about 99% ... but there's always that ONE time when I'm distracted by a pretty redhead, or REEEEEALLY need a cup of coffee, then it makes my dancers all look like Elaine Benis.