Had the STD M2 years back and also the $20K Ref for a few weeks.
K&T are great guys to deal with and I got to meet Taras in Atlanta in a Home of a friend showing off his new speakers. Nice friendly chap that loves music and easy to talk to.
All reports on this Teo cable is as I heard them. It's like installing a great 300B tube into your system. Real life like sounds that cause you to know you made a great buy by owning them.
One of the few audio mistakes I have made was rhe ridding of my AN 300B amp and the Teo StD MK2!!