I've tried 3 cables here. The stock dCS, Cardas Lightning 15 and Purist Proteus Provectus Praesto.
The Cardas improves on the stock (nice upgrade $250), the Purist are even better, but at about $1000 each I think.
What you'll here is more focus, more timbre, more detail...Good clock cables are a big deal from my point of view...