It's worth it just for the sound. But, like others have mentioned, it goes well with the AUT Cooling Plate. Normally, the AUT Cooling Plate has a type of funnel that channels air directly into the opening of the stock air box. When you take all that out and replace it with the K&N FIPK, this funnel dumps the cool air directly into the path of the filter. Here's picks of both on my car:

 

times new roman the second pic shows me exactly what i wanted to see. i wanted to make sure that a strut bar would clear the box. nice. i will be ordering this soon. where is everyone ordering theres at??

 

ebay is the cheapest around