So you'd say get the 200mm f/2 so I can have that crazy f/2 while still having a 400mm f/4 and a 300 f/2.8? I occasionally shoot a soccer game or something, but do a lot of portraiture and stage photography.
That's up to the individual really, what I would do is keep the 70-200 vrii and get the 300 which is better than the 200 with TCs, I would sacrifice a stop at 200, but would be able to reach 600 if I need to... and would have the same handheld ability as the 200. It really has to do with the type of photography you do and the subject distance that suits you, IMO the 200 and 300 can be used for the same purposes while the 400 is a real tele which aims for real reach, that's why I use more often APS-c than FF with it. Now I've listed the lens (here in Lula) and will replace it with a 300. It's just that my needs don't justify its use.., with the 300 I will be using FF more and I can cover (just) whenever I need a 600. If I was doing wildlife or football or racing photography, I would never let the 400 go. The thing is that with the 200, I would need a second (longer) telephoto and this can be a real pain... Regards, Theodoros.