Like the sig says, call me "Mazdaspeed Accessory Guy"!!
I like the Mazdaspeed cuz it gives a nice throaty growl and just knowing that it was made by Mazda. The performance boost isn't huge but it does feel a little more peppy during acceleration. If you really want "more" performance, go with the CP-E intake. People have been really happy with it but seriously if you drag race one with the Speed and one with the CP-E there will probably only be a difference of 1.23452312e-8 seconds. You're not going to see huge gains as you would on other vehicles.