Let me start off by saying that I agree with everything on the other reviews to date..... I've had a lot of hand ported saws in the past and was looking for someone that was up to date doing cnc porting. I've seen the difference in the racing world, so I figured there would be a difference here also. I ran Friends new 500i with a 36-in bar and was a little disappointed. I had already ordered a new 500 I. As soon as it arrived I sent it to Mike @309 machine to have it ported. I had already ordered a Max flow air filter kit and an Egan straight shot muffler cover. I ended up running it for 5 days straight with a 28 inch light bar and full comp chain doing storm cleanup in Western North Carolina. I'm not at all disappointed in my new 500i, and I don't think you will be either.....