So, my two new Vovox cables arrived today - 1 speaker cable, 1 instrument cable (item 195585).
Switching over from the Fender cables I had previously used, the difference was audibly obvious. Better sustain and articulation, more clarity in the middle and high frequencies, more solid, present bottom end (5 string, tuned to low B) and more of the character of the bass itself (Warwick Streamer).
Construction - solid, yet flexible. The jacks are reassuringly well-constructed, and they fit snugly into the sockets.
So far, I haven't had a chance to test durability; I will update this review if I need to add anything else.