Marantz SA7 S1 - Use of external clock

I was wondering if anyone had tried an external clock with this unit(or the SA11 S2 which also has this facility). What clock did you try or do you use and what are the sonic benefits if any?
Why? This player is state of the art. Just enjoy it! Buy some new CD's.
I would to know this as well. Don't get me wrong, I love the player but, since this feature is offered, I am bit curious as well. HI-FI WORLD paired it up with a Grimm Audio CC1 Clock and gave it five globes-which is an excellent score. That was on 5/09. Perhaps something is even better now?