In early march I was shooting Leopard in Northern South Africa (Mala Mala & Londolozi), with me was a Pro Photographer, Greg DuToit, he had a Nikon D3x with the Nikon 200-400f/4, I was using Two Canon 1Dx with the 200f/2, 300f/2.8 V2, 400f/2.8 v2 (The 200f/2 I had set up to my 5DMK3)(the 600f/4 V2 I had but mostly didn't use, too long on this trip), it was for me a perfect example while shooting of the value of this particular Lens (the 200-400), 1 Body attached to one Lens that covers 200-560 at between f/4 & f/5.6, for a Wildlife shooter to be able to Frame your shot as close to exact as possible in Camera, without having to shoot too long, or too short, this is it, flexibility, but yes, that flexibility comes at a cost, but that's life in general, not just in Photography, this will not be an everyones Lens like the 70-200f/2.8 L II or the 24-70f/2.8 L II, the new 200-400f/4 (1.4x) is a specialised Lens that will suit a particular type of Shooter, Wildlife & Sports & the 10k-12k price Tag isn't going to worry too much the shooter that's really interested in this Lens.