As I understand it Centrino is a standard. So you wouldn't have Centrino in your system but a group of parts that together are the idea behind Centrino.
I think there are three parts to the idea ...
Intel Wireless (I think)
Dont remember the third :/
So the based on that there should be no difference cause they are both Centrino in theory
You do have a difference between say intel card and dell card (dunno who manufactures their cards). From what I hear both perform the same pretty much.