This not the most scientific assessment, but here goes. I just put platinum electras and electra 7s into my system and am very impressed. Now, to be fair, the platinum electors replaced an old synergistic research master coupler II on my DAC and an Oyaide Tunami GPX on my pre so they should sound much better. But I recently tried some comparably priced Acrolinc PCs in this system and I think the Wireworlds give a bit better clarity and body.
The Electra 7s replaced stock power cables on my mono blocs - I was waiting for the WWs so toughed it through the stock cables. As expected, significant improvement all around. But what really surprised me is that I put an Electra 7 into my Isotek Aquarius conditioner in place of a Harmonic Technology Fantasy AC 10 and to my surprise I felt the whole system benefited. I do think the system gains from the progressive use of the WW PCs.
For the PCs I am using 2m runs as per WW suggestion even where I could have used shorter runs.
Finally, I replaced an Acrolink 7N-A2070 inter with a WW Platinum Eclipse. This produced an obvious improvement in detail, space, and body. It will be a few weeks, but I plan to try to A/B the platinum eclipse with my Audioquest Sky.
Overall, I am very impressed by these cables and extremely pleased I bought them.