Just wanted to say that the new 2x III Canon Extender is an awesome piece of glass.  I used it in Reno during the 48th annual National Air Race Championship in September and was blown away by its quality and performance.  The weak link is me and I was working on that when the accident occured.  Under low light I still got some quality shots.  I used the 2X III extender with my 70-200 f 2.8 IS USM II with my 40D Canon camera.  Canon, you did good....