Upgrading Speaker Cables: Wireworld Silver Eclipse or Transparent Audio Ultra?

More than 15 years ago, I bought a set of speaker cables to accompany my then brand new Revel Ultima Studios and Krell FPB amplifiers.  While I continue to adore the sound of my system, I know there have been a lot of advancements in cable technology this century.  Consequently, I believe that a [relatively] low cost upgrade would be a purchase of new speaker cables.  (I have no intent to replace either my speakers or my amplifiers at this time.)  I live in an area that is several hundred miles distant from any high end dealer, so doing a sonic audition of cables is infeasible; moreover, I could not duplicate my combination of other sources, amplifiers, interconnect cables, and power cords -- as well, of course, of my room environment.

All that being said, I have done tons of reading about speaker cables these past few months.  The result of my efforts has been to narrow down my two upgrade choices (both bi-wired) to Transparent Audio's Ultras and Wireworld Cable's Silver Eclipse.  Coincidentally, their respective MSRPs are between $50 of each other.

Ideally, I would love to read responses from other Audiogon members who have actually auditioned one cable against the other.  That is likely to be nigh unto impossible because I have been unable to identify a single dealer who carries both lines.  Consequently, I would be delighted to receive anyone's thoughts about the pluses and minuses of each individual cable.

Many thanks to all who provide their much appreciated insights!