Hi, this is a bit late answer, but,
I have been using Cardas SE9 for some 2 years, since my previous speakers have been internally wired with SE9. Compared to Kimber 4 & 8 VS in my setup much better. Now i use it with John Blue JB3 small 86 dB widebanders, and it works there really good too.
I dont quite understand why Cardas recommends it for ~90dB speakers, since it works with my, admittedly small and easy to drive 86 dB widebanders too. Maybe i will switch once to Neutral Ref. speaker cable but 2x4m Neutral Ref. vs same length SE9 is a bit difference in price.