I’m looking to add a 300mm lens to be collection. My primary use would be youth sports. I’ve got the 70-200 VR, but have found it to be a bit too short. I’ve added a 1.4TC, but when I’ve done that, the AF speed on my D200 seems to leave me with too many soft shots. I can’t be sure if the softness is due to the TC or the AF slightly missing. I know that the 300 f/2.8 VR (or Sigma 120-300) would be perfect, but given the more limited use, I can’t justify the cost. So, my main question is this: Is the focus of the 300 f/4 about as fast as the 70-200VR (without TC) on a D200? Thanks.