Changed to this from a K&N panel filter. No noticeable increase in performance.
The fit was a bit tight, at least on my car. It looked like the pipe that attaches to the filter might have been welded on at a slightly cockeyed angle. It was a little tough to squeeze the filter element on and it does not fit on straight. Functions just fine, though.
The great part about this product is the sound! You can hear the turbo whine and the blow-off valve very well. It is not so loud that it is annoying, though. Also, I'm sure it will be very easy to see when the filter element needs to be cleaned (I forgot to clean the panel filter regularly, and boy was it dirty when I took it out)!
Worth it just for the sound!
Rating: [4 of 5 Stars!]