I already own the 70-200 IS II and I generally shoot daytime soccer and nighttime (flashed) football. For most of the football fields I shoot at the f/4 would not be sufficient, but since I normally shoot flashed football the f/4 should be fine.
I am looking to get additional reach and the 300/400 2.8 lenses are out of my price range. Would I be better off using the 70-200 with the 1.4 TC or the 300 f/4? Will one focus better than the other? What about IQ?

