I've been an Audiogon member for many years, and don't post much, but I just discovered this thread, and would like to contribute.
I met Brian Walsh (Essentialaudio) when I purchase a Kuzma 4-point tonearm from him some years ago. He introduced me to Teo cables. He could have easily contacted me and asked me to post on this thread, but he didn't. I found it accidentally by myself, because I like Teo cables (as well as many other brands of components), and therefore occasionally search the forums for discussions on them.
I was immediately blown away by the standard Teo ICs, compared A/B with the Kubala-Sosna Emotions and Elations, in my system. I liked them so much that besides replacing every short IC with them, I convinced Teo to make a 6.5 m pair (apparently never before done)to reach my CAT JL-3 monoblocks. The difference was nothing short of phenomenal. I have not even thought about auditioning other cables since then. The Teo standard ICs, at ($2500-$3000)/m, I actually think are a great bargain. Prior to the Kubala ICs, I had high-end Transparent Audios (can't remember which). Kubala blew them away, Teo blew the Kubalas away.
I had Kubala Elation speaker cables connecting CAT JL-3 monoblocks to Acoustat Spectra 66s when I first auditioned the TEO SCs. The Teo standard speaker cables were initially dramatic in comparison, but I ultimately concluded they lacked the smoothness of the Elations, despite having some other real positives, mainly a dramatic "presence." Brian subsequently lent me some Teo reference speaker cables to try. I evaluated them at my leisure in my own system, and ended up selling the (excellent) Elations and keeping the (yes, even better) Teos.
I'd also like to comment on the toxicity issue. I'm not an audio dealer, and have no dog in this fight. I'm a microvascular surgeon, I have an undergraduate degree in chemistry, and I think I'm capable of understanding, in general terms, the issues involved here.
Many things are potentially "toxic." I personally would not consume Indium, or intentionally breathe it for long periods. I would be even more careful about not touching hot vacuum tubes, or letting my 2-year-old or 5-year-old do so. I would be yet more careful about not putting my fingers or metal objects in electrical outlets, or on bare speaker terminals.
While it is sometimes easy to prove a positive, such as something is dangerous, it may be impossible, from a practical standpoint, to ever prove that something is completely safe. It all comes down to a risk / benefit analysis. My feeling is that these cables sound so good that their sonic benefit outweighs any of the theoretical risks discussed here.
Having said that, I wouldn't let my kids chew on them. I also wouldn't let them touch hot vacuum tubes, explore electrical outlets, or take a bath without an adult present.