"i doubt those idiots at mazda made something so bad that an aftermarket makes 20 more horsepower... in a car that is known for its power"
I wouldn't call them idiots; If you are Mazdaspeed trying to sell your own aftermarket intake system, you can make one with less compromises to put on your stock car and give the end user something worth buying. Good marketing in my mind.
It is not like it needs more power from the factory, the car has so much torque and power stock, that it electronically torque limited in the first 2 gears so you just don't fry the tires. Haven drive one while figuring out what to buy, (and I also has a friend who owns one) it really comes on in 3rd gear and above where the limiter is defeated.
I wouldn't challenge one at highway speeds unless I wanted to be looking at his tail lights. Look at the0-60, 0-100 and 0-130 times in the mags that test that high and you see where 3 really becomes a beast. It really needs AWD so they could totally uncork that motor.
That all said, I bought a GTI for its blend of attributes; if I really end up wanting more power, I will go the APR re-flash route which gives a lot more bang for the buck than an intake.