ATI 4890 XFX Extreme edition- OC?

Hello All,
I guess I got lucky this time. I decided to order a recertified 4890 from NewEgg. It came yesterday, and lo and behold, 875 mhz stock clock, I got an extreme edition instead! hurrah!......? To be excited or not is the question. I think I read somewhere that it is less likely to get 950/1000 OCs out of already factory OC'd cards. Is there merit in this charge? Or will I still be able to tune this baby to damn near 1ghZ?

P.S. OC CPU first, then GPU? Or does it even matter?

I got mine running at 1GHZ core.

You get more increase in performance by cranking up the core clock than the mem clock.

Below is a reference/benchmark results on 4890 OC for both core & memory.
http://www.anandtech.com/video/showdoc.aspx?i=3555