I have used rca nordost red dawn, xlr nordost spm, XLR Kimber 1120, and XLR harmonic tech truthlink in my system. In direct comparisons, the spm is definitely the best, followed by the harmonic tech truthlink, then red dawn. Note that I rate harm tech XLR above nordost RCA which is not a valid comparison given my system is a true balanced design. I tried some kimber 1120 XLR's, and those sounded about equivalent to my nordost red dawn rca's. Cables are truly system dependent. Should try and contact the manufacturer and find out what they demo or voice their speakers with. A cheaper cable that is matched definitely outperforms an expensive bad match.
Don't mean to knock your system, but you might try swapping your ls-2 for an adcom 750 sometime. According to one of my friends who did this exact swap, you may see a significant increase in transparency. I'm just a messenger !