Friend has a b18 swap in his 2000 civic. I believe it's a GSR engine from a 94 model?

He want's to change the cams but decided to go with the CTR cams instead of the Skunk 2 cams. He was told that the CTR was a better choice because it was OEM with the valve train...and since Skunk 2 is after market you need more modifications to get more potential out of them.

I'm just curious to as why? Or did I just answer my own question? And what kind of other MODs would have to be done to squeeze the full potential of the Skunk 2 cams...