Okay, so I think I'm sold on a 300mm f2.8. I've been trying to read as much as possible on it, and I've at least narrowed it down to the Nikkors - specifically the newer VR models and the AF-S II (ie/ I've eliminated the Sigma 120-300 and 300 prime, as well as the AF-ED Nikkor). Please, can anyone that's used these Nikkors comment on how they compare for SPORTS use specifically? I'll be using it for baseball, football, hockey, and more. Right now I have an AF-S 300/f4 that I've enjoyed, but would like the ability to shoot (1) at f2.8 at times and (2) with a TC at f4. HELP!