Well, I have not yet purchased any cables for the Legacys, but I just yesterday received a single run of Alpha Core Goertz MI-2 speaker cable for my center channel speaker in the front system. The MI-2 replaces a run of Speltz anti-cables which have done pretty well.
I have only so far listened to one movie, but I do believe the Goertz are going to knock off the anti-cables. The highs are definitely cleaner and better. It actually seems like there is MORE high frequency information there, if that is possible. This is not to say excessive HF response, and I do not detect any added sibilance.
So, as a result of this improvement in the center channel speaker, I am leaning towards the MI-2 for the Legacys in the back system. The only fly in the ointment is that the center channel speaker only goes down to about 55hz, so I can't tell anything about the MI-2's deep bass prowess.
My main contenders are now the Goertz MI-2, Straley Reality cable, Audio Art SC-5, Audio Horizons, LAT International SS-800.
Any thoughts?