Smooth, in time, and with very good music interpretation. Additionally, there is a softness in the finality of executing moves. A combination of good technique and artistic expression while the leader "gives way" makes this great to watch!
Thank you for this wonderful analysis of what we're seeing here... ...'cause too many people are unwilling to look at the fact that what we're seeing, is folk/social dance modified (abstracted?) to serve the viewer. All too often these posts end up bombarded with complaints that this isn't "real Hustle" or... complaints that the music doesn't reflect some folks need for some type of crystalized (and therefore LIMITED) nostalgia. Competition, performance, and spectacle is fantasy for the audience, and there is nothing wrong with that. Thanks for your comment... it's refreshing.