Has anyone heard and or even tried Wireworld cables. I see that they are recommended cables for MBL electronics and were used by Stereophile in their test with Jeff Roland Concentra and once again in the recommended components May 2002(see below).
Are they any good?
I have been using Wireworld Atlantis II interconnect from my phono preamp and my CD player to my preamp and have been very happy with it. Several years ago I audition numerous interconnects from The Cable Company (highly recommended) in the $100 price range including Wireworld, Nordost, Cardas, Audioquest, MIT, and Tara Labs. I liked the Wireworld best, it was very neutral and the most coherent and made all the others sound confused and conjested by comparison. The Cardas would have been my second choice. I found the MIT to be by far the worst of this group. Recently my 13 year old Rotel CD player stopped working, so until I can replace it I substituted the Wireworld cable for the Audioquest Topaz I had been using from my tuner. I immediately rediscovered how good an FM broadcast can sound. The Wireworld Atlantis II which cost me $90 per 1 meter pair was way better than the $40 Audoquest Topaz. I highly recommend the Wireworld Atlantis interconnect.
I run WW interconnects exclusively in my system (the Polaris III and the Eclipse III). Over the years I have done shootouts between these cables and stuff from Harmonic Tech, Silver Audio, Nordost and Cardas. The competitors were all well made and worth the money, and in some cases they did things better than the WW cables. But these things always came with unacceptable tradeoffs. The Nordost (Blue Heaven and Red Dawn) give better midrange definition but at the cost of accentuating treble grain. The Silver Audio has excellent clarity and separation of instruments, but an overall cold and abrasive sound. Harmonic Tech's cables sound mechanical in my system and the bass is mushy. The Cardas (Cross) has a very clean treble and nice midrange, but even mushier bass and reined-in dynamics--the music actually sounds slower somehow. I don't think the Wireworld cables are absolutely perfect, but unless you have thousands to toss around on cables, along with day after day set aside to do shootouts, they are quite easy to live with. I find the Polaris is voiced a little more forward; the Eclipse is slightly mellower with deep powerful bass. They're both excellent values for money. I do hate the RCA plugs, they're big and unwieldy and a pain in the ass, but then I hate locking plugs worse--they always seem to get stuck and then you need pliers to get the damn things off your equipment. Hope this info helps.

By the way, I understand different cables work better with certain equipment. I suspect WW is best suited to beefy solid state amp-based systems, whereas some of the unshielded cables and silver/hybrid cables may be better suited to delicate tube systems. Just a theory.
My experience with the upper end Wireworld cables is that they are generally competitive with others in their price ranges. I used to use their Gold Eclipse IC but have since moved through several others and now use Quattro-fil (and sometimes AZen Silver) which I think provides better focus and detail, but not quite as robust or powerful as the Wireworld.

But I still use their Silver Eclipse 3 speaker cables and haven't yet found a better match with my Talon Khorus (I've tried AZen, Analysis Plus Silver, HT Pro-9, Audio Tekna, Magnan and some others. The Wireworlds do nothing very wrong and most things very right, aand straddle the line between detail and musicality with great grace. They imbue the music with an addictive liveliness and energy. No grain or harshness and very quiet.

Would I buy them at full new retail (~$4000)? Probably not. No cable should cost that much. But at discounted used prices they're really competitive.

I've also used the Polaris speaker cable. It's more laid-back and less neutral with it's energy focussed more in the mid bass. I think it has stiffer competition, at least at its new price.

Wireworld has just come out with their new series 5 cables which I haven't heard.
As always, like everything, cables can be system-dependent.