I realize that with any extender there is some loss of quality, BUT... Just yesterday I saw some amazing shots from someone's recent trip to Africa, Some of the pictures were unreal, Like 5 zebras lined up just waiting for there picture to be taken. Anyway this guy is a very good photog, and a enjoy his work. So I was picking his brain about how he liked different lenses and what not, and found out, that he was using a Canon D1s MkII, a 40D, a 400mm prime, a 70-200L 2.8 and an EF 2x extender. I could not tell the difference between the 400, and the 70-200 with extender. I did not know what lens he used when I was looking at the photos, I guessed probably around 400mm,(ive been to South Africa and lions always stay a good distance from the road, probably just to spite photographers.) The point is The shots were great, and the quality of 8x12 prints was fantastic, and I was viewing them while holding the prints in my hand. I know that people often say that the quality of the 2x is only acceptable but not great, I would like to say that the quality is VERY GOOD, and now that I have seen the results I can reassure anyone who is on the fence about buying one.