I noticed a very slight difference when I did the stage 1's on my NA 2.0. Definitely not worth it unless you are installing yourself. You will need a tune to maximize benefits.
Walter Marcy did a lot of testing with the Crane cams... you will need to adjust them to also achieve the best curve.
I would suggest stage 2 cams if you plan to stay NA
2.3 Duratec, FSWerks 387whp/328trq 21psi