Lovely upgrade to the standard cable.
Honestly, all the KZ brand IEMs should come with this cable from the start. The standard cable is rigid and annoying, and sits awkwardly around the ears.
This cable fixes all that, and brings everything to where it should be. Chord is a good length (I'm 6'4), it's soft and malleable, the loops for the ears much tighter, but soft enough to fit and sit perfectly.
I didn't notice a difference in sound quality, but I haven't tested for it. Sounded fine when I used it live.