Occasionally I find situations photographing flying birds that need a 200mm lens. An example would be on big sea cliffs with strong winds. I use a 200mm as its easier to track a non linear flight than the 300 f 2.8. I have got some great shots with the EF200mm 2.8L but I wonder apart from the weight and cost would a EF200 f 2L do any better with focusing speeds ?