To wrap up my listening thoughts ...
They aren't harsh, just transparent. Not thin or stark sounding, either.
The tonality sounds right. The bass is well defined and I don't hear any loss of bass power reported by some.
It took me a while to get my head round what they actually do, compared to my excellent IXOS Ixotica cables (something like £300-400 a pair when new, I think).
What they do is move you forward a few rows in the concert hall.
The IXOS place me about 12-15 rows back from the front of the front stalls.
The SPOTFIRE move me to about 3 or 4 rows from the front.
So they are more immediate sounding, slightly increased detail, immediacy and transparency. Less of a cushion of air between me and the performers.
Imaging-wise, the SPOTFIRE are a bit more focussed and with more clearly defined soundstage placement. Just what you'd expect from moving nearer the concert platform.
The IXOS place me quite close to the music, the SPOTFIRE put me even closer.
Where do I want to be?
Well, tbh, I still really like the IXOS and I suspect the SPOTFIRE place me a little too close for comfort some of the time.
On the other hand it would be nice to have the option of choosing!
Either way, the SPOTFIRE are a really excellent, genuinely high end cable imo. Whether or not they tick your own specific boxes only you can decide!