Cellorover - thanks for the input. All demo cables and power cords had well in excess of 500 hours each. As mentioned in my post, I was expecting the speaker cables to be the most dramatic by way of improvement. Unfortunately, they were not. I have been auditioning a new pair of Transparent Reference speaker cables and even with only 20 hours on them, I prefer them to the TQ Black Diamond cables.
I am also getting a set of the new Audience speaker cables next week to try for 30 days.
I may circle back and try the TQ speaker cables again. I am totally sold on the interconnects and power cords though!