So I broke down and picked one up for a WWII re-enactment coming up in a week. Last year my 200mm was a tad too short for the combat scenes. Here's a shot that was cropped to get closer to the action. This year with the 1.4x converter I hope to get my shots a little closer to the action. My primary concern was that the converter would cause CA around the edges and it would be too noticeable... that and I feared, from what I read, that the IQ would suffer - the image wouldn't be as sharp. I shot some test photos and I think it's going to work out amazingly well for me. The sharpness is fine and I don't see any horrible CA around the edges, which might be because this test shot was taken with my 1D4 which is a 1.3 crop sensor. The CA might be getting cropped out. Here's a sample shot of our local flying rats sitting across the pond on a neighbors lawn (thank God they aren't crapping on my lawn!): Larger: http://intempus.smugmug.com/photos/846180543_4XZRX-X3.jpg I'm stoked for the event next weekend. I'll also be sporting my new Black Rapid dual strap system (two R4's with the CoupleR system) so I can have both my 5D2 and 1D4 with me with different lenses. I should be set to capture all the action.