I did A/B the Elco and Acoustic Zen (months ago). The Elco seemed to be a bit more up-front and feature the mids more than the Zen. The Zen's mids were more recessed and it may have had lower bass (not necessarily more prominent...just lower in frequency). I preferred the Elco in my system, but it really is completely dependent on music tastes and your system. The Zen would probably sound perfect in a system that is already a bit forward. It's a great sounding cable in every way...it's just a little laid back in my system. I didn't A/B the Cardas with either, but I'd say it is more similar to the Elco as far as balance goes. The Elco gives the impression of being more detailed (though the Cardas is very detailed), though it doesn't seem to capture the lowest bass octaves (which is okay, cuz my speakers stop at 35hz). I'm not sure if the perceived detail is due to accentuated highs or not. It sounded a bit edgy at first, but that wore off after using it for a few weeks. I used the Cardas for a year before I got the Elxo and Zen and enjoyed it, but I still haven't gotten around to comparing it directly to the Elco or Zen. It's a headache, but one day I'll get around to it.