Are there any differences between these intercoolers?

I've just taken my UK99 one off and other than straighening the fins, is there mush i can do to improve it? How about swapping it for an STi one?

 

they look the same but the core is different on the STi & it is believed to be more efficient

 

I've got an STi one on my '98 car. It is slightly different, and I believe the pipework below it is better too.
I was told by a reliable source that it allowed my car to breathe better, when it was remapped.
Alcazar