Totally glitch-less here. The trick is the same for getting glitch-less transitions across any musical boundary. Timing in hitting the chords, and hitting the buttons.

It's often the case that, at turnarounds, chords change quite quickly. On top of that you have to hit fill buttons, and if using the CS, you have to hit that TOO. The trick is learning WHEN. The Roland CS (and I think the Korg too), all it needs is a hit of the Play button at ANY TIME in the bar before you need it to happen. Then you go through your usual timing for playing and getting the fills.

The Korg has a distinct advantage over the Roland's. Along with switches for Variation (with autofill), you can activate the CS functions with footswitches. So you get a hands free transition, that allows you to concentrate on playing timing without lifting off the keyboard at all! The 5 switch footpedal has many uses!

The thing about BAD operation of timing on the CS is, you'd be surprised, if you play an evening back, how often you can hear little timing glitches across fills. I hear them on user demos all the time. But a CS is going to make them more apparent to you, because it is going to do the same glitch, if you initially made it, EVERY TIME IT REPEATS...

That's a lot easier to spot than a different glitch each time (or now and again). But nail the fill timing and chords, you NEVER get a glitch.