Cookie has both versions of that lens and carries the newer twist unit on a full frame body (7D) and the extend a tube on a crop unit (70D). Short of setting up an extremely controlled environment, I don't see any obvious difference in image quality between the two. For off hand shooting, if I get a chance, I prefer the older unit. With its longer dimension, I can get more stability by gripping the camera body with the right hand and use the left to grasp the extreme far end of the lens hood. Don't think one is making a serious error at all by going with either version.
Last edited by 1minute; 07/11/19.
