any benefit in a double bi-wire of 8TC?

You might even try a double-bi-wire set of 4TC. For some reason, 4TC sounds completely different (WAY better) than 8TC in my set-up.

In case you want to know, I'm using a NAD 304 integrated and Triangle Zerius 202 speakers.

...And a single-run of 4TC (bi-wiring, while necessary with my B&Ws, doesn't seem to make a difference with the Triangles).

Good luck!