Hello Pastor Bob. Good to read about your experience with the Dueland 16GA cables and interconnect. I learned about them several years ago and read some stunning reviews. They were tinned copper with oil soaked shields in those articles. The reviewer even challenged them against some $14,000 cables but later came back and adjusted his thoughts about them. After living with them a while longer he felt the Duelands performed well but did not outperform the $14k cables. Here is a copy of his review. It really legitimizes what you're discussing.
Here is my experience with them: I had both speaker and interconnects made up and ran them on my speakers for a while. I noticed that I missed some top end detail but seemed to perform in line everywhere else. I re-read the review from The Audio Beatnik and he said he figured out that his speakers needed to be very efficient to get the best performance from them and mine were not efficient at all. I still have them boxed up and your note is making me think its time to pull them out again. My current speakers are more efficient and my system more capable so it will be interesting to see the results. Hope all is well and that this helps you understand the phenomenon of your Duelands.