I would guess that if you are going to spend that kind of money, it would be foolish to not follow the manufacturers instructions. I own 5A's and 1c's, and I never tried the 5A's non-biwire. I did own the 3A Signatures for a year+ and they benefited quite a bit with bi-wire, even when I was running two 2wq subs, and the high pass filters in front of the amp.
Will
Will