I was thinking about doing this to my stock struts last year on my 08 wrx. Talked to Devin at Speed Element and after much debate decided to go with the Tien Basics Coilovers instead. Came in cheaper than them doing the work for the Koni inserts. I am very happy with the choice. Major improvement over stock, height adjustability, and maintained a comfortable ride. Which was very important since this is my commuter.