I have multiple sets of Zen Styx(M22759/11-8).  The Styx do not have a boatload of unnecessary insulation and fillers to "bulk them up" to the size of garden hoses or larger to make them look impressive or more expensive.  The insulation they do have is PTFE which allows it to be relatively thin compared to other insulation materials to get the same insulating characteristics.  Which BTW, is more than adequate for audio purposes, and is rated for 600 volts.  Therefore the "break in" phenomena is less than just about every other boutique speaker cable in existence.  
I have observed a smidge of smoothing over time, but IME, it has not been a dramatic change.  

You can try a twist of the two conductors together as opposed to keeping them spaced 6" or more apart, and produce a difference in the sound - give it a try and see what you think.

I addition, I use this wire for internal wiring of all my DIY box speakers and for my DIY OB speakers as well - or some version of it.. smaller gauge 12 or 10, etc.  The Styx are 8 awg.

Well, I have had a different experience with the ZenStyx. They took a long time, a month or more, to reveal their bass to me. When they did break in I really liked them and used them for some time. . . but over time I kept chasing a treble edge that I thought was tubes. . . or power cords. . . or interconnects. . . but when I put in my former (and now current) speaker cables, PS Audio xStream Statement, it went away. So I ended up selling the Zen Styx, and used Mapleshade Audio Double Helix Plus speaker cables for a long time and use those now in my audio-visual system, and use PS Audio xStream Statement in my main audio system.

I every instance, tizziness in the top end is not in the ZSTYX, but rather the room or speakers or something else. If you have any doubt about that whatsoever, feel free to come by for a listen. The other brand speaker wires are filters compared to ZSTYX so they attenuate the problem that the ZSTYX revealed.  Lon, as an example, the HR-1 have always had a characteristic 10dB peak at around 12kHz.  ZSTYX just let you hear it.  

Steve

My cables have been congested for a long time, over 400 hrs. Over the weekend I added another 24 hours with the volume cranked and thankfully, they have finally opened up. The tizzies have diminished, the sound more organic and full bodied. The fellow that chryoed them warned me that they take at least 600 hours to breakin and after 400 hrs, I was loosing patience. The Teflon jacket, it’s my understanding, extends the need for breakin. In any case, I’m pleased to report that I’m very happy with the outcome - these will be keepers! Regarding the sound quality, no complaints, no peculiarities - but, these definitely need a lot of time to get the best from them! They are precisely as Steve describes them, at least in my system!

My ZSTYX were pre owned, so I really can’t tell how long it took for them to settle in.  But I do agree that they add nothing and are transparent to upstream components.  Room acoustics is another matter altogether.

I’m running Omega S3HOXRS, the combination of the ZSTYX and the Omegas make for an incredibly transparent and fast duo.  Then I added Furutech connectors, put a light twist in the cables and after I did that the first 10 hours were... brutal.  I was told that the connectors would take at least 200 hours to settle in and that by re-working the cables would be a contributing factor.  After 25 hours the worst of it was over.  One day I turned the system on and the change was dramatic.

I’ve yet to find that the ZSTYX contribute to any harshness, tizzyness or hardness, and they do not limit bass output at all.  They truly get out of the way.

Recently I have posted about my experience with the GZ34 Metal Base and some rolling of input tubes.  You just have to hear how liquid and complete the sound is to believe it.  The differences were immediately and clearly discernible, and that’s what I want the cables and speakers to let me hear.

As for the room acoustics, yes some attention is needed.  In my case I prefer to deal with that in ways other than cables or components because, based on my experience, trade offs are introduced that may require additional and possibly ongoing attention.  That can become a very expensive journey.

However, I do understand that not everyone can deal with room acoustics with treatments.  So alternative solutions may/will be necessary in those cases.  But in those cases it’s not the ZSTYX that’s the problem, it’s something else.

I'm glad everyone enjoys them so much. They're my third favorite speaker cables, definitely good stuff.

PS Audio xStream Statement, and Mapleshade Audio Double Helix Plus.

I couldn’t say what difference was in putting the mild twist in the cables as I did that in conjunction with the connectors.  Originally I had two individual conductors per side and I wanted to configure the two into a cable.  The objective was aesthetics more than anything else.

I had these ZSTYX my SE84UFO2 without any connectors on the amp end, the ones that were on when I got the cable were a little loose in the posts, so I removed them.  When I got the UFO25 I had trouble getting the bare end into the binding post so I decided to put connectors on.  I had misgivings about that.

Initially I was disturbed by the sound with the Furutech connectors on the cable.  But the cost, even though it was substantially less than the WBT, caused me to suffer through the first 25 or so hours.  I was encouraged to be patient which is not one of my better virtues.

Your right, the dramatic change came as the Furutech connectors burned in, never would have thought the difference would have been so dramatic.  And there also was a difference from the original configuration.  I feel that the effect of the Furutech connectors was a greater sense of transparency, a greater sense of the cables disappearing.  

Initially the sound, with the new Furutech’s was muffled, dull, way worse than the original configuration, my heart sank and I’m sure I uttered a couple of colorfull expletives, silently.  That initial sound gave way to a squeaky clean sound that was a little light on density and bass.  The next change was that the density and bass and fullness came back only with greater transparency and clarity.

The Furutech connectors are gold and eventually I was so impressed that I bought a set of binding posts for my speakers but I have not installed these because I may end up with the Big Betsy’s and I’m reserving them just in case.