Well I just got my new XCR exhaust in and couldn't wait to try it out. The instructions were very good and the install only took a few min (woulda been really fast had I not been searching for a dropped bolt) and it went together nicely. I fired the pig up and it sounded great. The XCR produces a nice deep tone with the arrestor in. I have never heard a White Brothers pipe on another L, but I have heard the E2 on a Yamaha Raptor and the tone is very similar. I took a spin down the road and I was amazed at the performance increase! No more throttle lag, and almost no decel pop and I have a stock carb with no mods. On the way home I suddenly heard the bike get noticeably louder and thought nothing of it having only a few miles on the new pipe. When I got back to the house I saw my spark arrestor was missing. After an hour or so of searching the area where it happened, I returned home empty handed. The pipe without the spark arrestor is quite abit louder, but the performance increase is noticable. As I ride in BLM and USFS areas where they do check for arrestors and noise levels, riding without is not an option and I like to have a quieter machine anyhow. I called White Brothers to see what they would be able to do for me if anything. I talked to Josh, and after 20 seconds of conversation he is sending a new spark arresor to me. He did advise to check the bolt for tightness before a ride. I have to give a big kudos to Josh at White Brothers for his customer service. There was no questions or a hard time, just a simple solution. Based on the customer service alone I would recommened White Brothers to everyone. With the ease of installation, the performance the choice is a no brainer.