I spent hours watching some really great fliers "click" with their routines..
That Wow factor truly is a matter of the flying emphasizing the musical phrasing. Addressing the mood of the song with the style of flying and then adding accent points where appropriate to literally punctuate the performance.
Paul uses soundtrack styles of music a lot which have natural builds and lulls which he takes advantage of every time.
Take the analytical approach to this. Looks at the performances you want to emulate and what you remember from those performances. I call them pop points. What was going on with the kite at the time? What was the music doing? What particular point of timing, performance or trick made this stick in your mind?
Paul's "Back to the Future" routine from a few years back had him doing a catch on 80+ ft lines. He'd tug the kite just before a certain point in his music and it would seem to take forever diving out of the sky into his waiting hand. The times I saw him do it, the catch was the crescendo and everything leading to that point in the music was just building to that catch. The timing of the catch was everything.
Watching John Barresi's looney tunes performance, the animation of the kite literally carries you back to the cartoon that sparked the performance. The kite becomes everything from Bugs Bunny's ears slapping Elmer Fudd's head to a chasing gait to even the flowers blooming after the hair tonic was applied. It all fits.
John's "I'm the Man" demo for the Djinn had a pop point for me as well. The diamond bicycle. The smoothness of that particular sequence within the video highlighted the entire sequence.
Watching Chris Shultz's Mirage stack performance is mesmerizing. The kites have a life of their own with a banter and playfulness that literally demands you watch. It's one of those moments where you forget you are recording and end up recording the ground or the sky while you just watch.
These are pop points for me. What do they all have in common? The motions of the kite whether difficult or easy, clicked with the music and the overall performance to create a memorable moment. It doesn't have to be an axel or flic flac. It can literally be a stop or sudden change of direction or speed.
Now when I'm listening to music I use for my demos, I find those accent points I want to emphasize and practice whatever move I want to do there around that point. Where do I need to be in the sky? What aspect does the kite need to have at that time. The pop points don't have to be difficult at all. One pop point I use in a song is an unexpected double cymbal hit. I time my approach loading the sail and flying slowly across the window (forwards) using each beat of the song to load the sail a bit more. On the double cymbal hit, I quickly accelerate the kite with each hit releasing the energy I've loaded up into the sail. It's not a hard move to do but when you see it timed with the music (and when I get it right) it just pops. You listen to the song later and the cymbal hits you never noticed before will stand out to you.
Bottom line is, Yes, there is technicality involved but those pop points are what makes a performance memorable. Placing them at strategic parts of your sequence will maintain audience attention and get you on the right track. As you start stringing these pop points together with cohesion and continuity, your performance will leap ahead with the impact you are looking for.
Personally, everything between the pop points, I fill with soul flying. I think Paul does some of the same approach. I'm under the impression John visualizes a grid in the sky and approaches it methodically with short sub-routines and transitions between them.