Anyone tried the Welborne Labs Power cables?

If so, what did they compare too?
I tried two 10 foot runs of their power cord kit on my Martin Logan Vantages--with active base units. Worked very well. Be sure to put some Silclear on the inside connections when assembling. I am not certain that I could compare them to another cord (The lengths were so long that I could not do an A/B comparison), but they definitely improved the entire spectrum of sound and not just the base.