CO vs. CG stepping for A64 processors

[imported_jediknight]

So I got my A64 3000+ yesterday. Want to know if this is a CO or a CG stepping one, and what difference it makes (ie. is it worth it trying to exchange for the other model?).

Serial #:
ADA3000AEP4AP

 

[ALIEN3001]

C0 - and no, it's not worth it, CG is just a little cooler (very little), can overclock better and is more compatible with certain memory brands.