Hi thieliste,
I used Straightwire Maestro (first) and Crescendo speaker cables (later) for years with my 5i’s. Very good. Preferred them to the Transparent XL speaker cables due to the great bass slam, but the Transparent cables are very refined, yet open sounding cables, and easily recommended if you have the $$$$. Wireworld cables tend to sound similar to Straightwire IME. Very good also.
I avoid Cardas cables like the plaque, although I own the Ayre K-1xe preamp and CX-7eMP player and Charles Hansen/Ayre loves Cardas cabling. Way too rolled off and closed-in sounding for me.
If you want a very low noise floor, detailed and incisive sound with a ton of air and a huge, layered, transparent soundstage, try the Synergistic Research Tesla Precision Reference or Apex/Element CTS/Atmosphere Level 4 speaker cables.
http://positive-feedback.com/Issue79/synergistic_atmosphere.htm
Best to you thieliste,
Dave