I have one and it works perfectly. You wont get any more performance out of it really. Just better airflow to the turbo. That goes for any intake or filter upgrade. Its worth the $50 for the filter. Get the cleaning kit. Ive already washed it twice since getting it. So really it pays for itself within a few washes.
It is a bit of a pain to get in the first time. Its a little lose so it wants to fall out. Once its in. It swells to fit better. Then stays that way.