The filter is open to fresh air at the front, I will take a better picture to show that opening.
I had the AFE which I was not happy with its fit and finish, this one is like day and night comparison in quality. The filter is made out of Nanofiber which is a Donaldson material and supposedly the best for filtering small particles.
Yes I did notice throttle response and the sound from the muffler is louder, the sound from the intake is kind of like a whooshing sound. I have not driven it enough to tell if it has any affect on MPG's.
I have a hydro-shield pre filter so you cant really see the blue filter.