Hmm, actually.. I adjusted the the gears and put in the new cams before doing a test run. Then later adjusted the cam gears back to zero cuz couldn't hold an idle with the adjustment (going to take care of that later) But noticed that the power went back to the stock feel. You may be right that it could be noticeable, and I just didn't realize it because adjusting the cam gears has QUITE and impact on performance (a very nice impact indeed). But as far as the mazdaspeed cams are concerned, if you can get a great deal on them, by all means, go for it. I paid WAY too much for mine.