I'm seriously thinking about making this move. I really don't like f/4 glass for my style of shooting. Though I do need focal distance at times, I figure I could hit my sweet spots with a 200 f/2 and 400 2.8 and using the 1.4 tc and eventually picking up a 1.7 tc. What do you guys think? Is this a reasonable move? Does the 400 2.8 live up to it's legendary sharpness status? Opinions welcomed.