It depends on what you're going to be shooting. I had the same dilemma, but it came down to which was more practical. The 400 was so tempting, but what did I need most, 400mm, or a sharper image, with faster focus, and a bigger f stop?





Since I do weddings, I went with the latter. Come to find out, the 200 is more than enough. I'd never be able to use the 400 at a wedding, in most realistic situations anyway. As it is, I was needing to step back more than I thought. I'm probably going to pick up a 1.4x for sporting events, as it's a cheap way to get out to 280mm. The 2x degrades quality a little more.


So in the end, it really depends on what you want to shoot. Both are awesome lenses, but the quality of the 2.8, mixed with the more useable range is what sold me.