Quad ESL57s and Anti-Cables?

Anti-Cables have considerably higher inductance than the Nordost's, with the difference being greatest if you don't twist the + and - conductors of the Anti-Cables together. In conjunction with the impedance characteristics of the Quad, which as in the case of many electrostatics decrease to very low values at upper treble frequencies, that will result in significantly less upper treble extension with the Anti-Cables. That difference will increase in proportion to the length of the cables.

Whether or not that would be good or bad in your system from a subjective standpoint is of course your call.

Regards,
-- Al

I'm wondering if someone could chime in and quantify the appropriate specs for cables suitable for the Quads.

I'm doubtful that it's possible to do that, in part because the answer would probably be amplifier-dependent. For a given signal level, a solid state amplifier will deliver proportionately greater amounts of current into the speaker as the speaker's impedance decreases at high frequencies. A tube amplifier, having significant output impedance, will do that to a significantly smaller extent. So the effects of the cable that would be desirable, with respect to tonal balance in the upper treble region, will be dependent on the type of amplifier and its specific output impedance. Also, it would seem conceivable that the sonic performance of some amplifiers could benefit if the cable provided the amplifier with a small degree of isolation from the capacitive nature of the speaker load, via resistance and/or inductance. In general I would not expect that to be predictable, though.

Regards,
-- Al