The best balanced digital link?

I have been using a 1mtr XLO signature AES EBU balanced ic between my EAD T-8000 and SF SFD2 series 3 for some time. It works so well that I've left it alone for 5 years! However all things improve, and the upgrade bug eventually catches up with ya. I wonder whether anyone else has found someting that really resulted in across the board sonic improvements? What is your current favorite and what did it replace? C'mon guys and girls- inquiring minds want to know!
i have 3 ref. digital cable and happy with them
-kharma grand ref.
-synergistic designer ref.squared.
-xlo limited edition
I have a NBS signature (1st version) that is excellent.
It beat everything I tested it against when I bought it
(including XLO nonAES/EBU). I cannot use it with my new transport (no balanced out, trades). I'm willing to sell
it for $500 (shipping included). Send me mail if you are interested.