Before installing the EVO, my Boxster had a subtle dip in power nearing redline. In my dynoless opinion, that dip is no longer present - the 2.7 pulls nicely all the way to redline with less variation than it used to.
Answers to questions you may care about, or may not:
Q. Does it seem quicker?
A. Yes, but only incrementally.
Q. Does it sound tremendously different?
A. No. Granted, I was expecting the great sucking sound I heard when I installed an Injen intake on my last car, so the subtle difference is far, far less than I was anticipating. My bias aside, I don't think you'll be blown away.
Q. Am I happy with it?
A. Sure. The install had a happy ending, and my car runs (completely subjectively, of course) a touch better than it did before I started.
Q. Knowing what my car feels like before and after, would I do it again?
A. Probably not.
Q. Would I recommend this to someone else?
A. Depends on what you hope to get out of it. Want the satisfaction of a job well done and the installation of a reusable cone filter (and potentially the privilege of fouling your MAF

)? Yes, get one. Want to feel power like you've never felt before tugging the fillings from your molars, ultimately filling the back of your throat with the bitter taste of fear, the tang of excitement, and the odd metallic flavor of decades-old amalgam? No, not so much.
All my opinion, of course. Your opinion, mileage, and overall experience may vary. Odds of winning depend on the number of entries, no purchase necessary, offer void where prohibited by law.