The Neptune Diamond is possibly a good cable for a very bright system. Not for a well balanced setup though.
Based on the immediate response and the number of responses you provide per day/week, I guess that you are a retired person and have enough time on hand. So I went back on your older responses and see that you have mentioned the same thing for Audioquest Hurricane power cord. That is when it struck me that it must be your age and your ears. With age people tend to lose the ability to hear the higher up frequencies. Your system must sound balanced for you, since you have hard time hearing those trebles. You keep recommending a certain brand of cable that is known for "highly resolving details", while PAD is known for it's lush details and Audioquest more for it's dynamic presentation.
At the same time, this thread is about a power cord for Accuphase. I don't understand how you can provide that specific recommendation, since you don't own an Accuphase. Don't you own a Boulder integrated with Wilson speakers? If you want to bash PAD, then we have a separate thread and you can post your opinions there.