So, I've got a 70-200 2.8 II, 6D, and a 2.0 Tele III, and many other lenses, but, currently nothing longer than that. I really want a 200-400 1.4 but am hesitating because of the price. But, I was talking to photo professor at a local big time university, and he said with my 6D, I shouldn't buy the 200-400 unless I also (or first) buy a 1Dx body. I was holding off until the next generation since I like the 6D sensor, although I realize the 1Dx can do other stuff the 6D can't do. Which is more important to own- the 1Dx or the 200-400 1.4? If I get the 200-400 is it that important to get the 1Dx? Thoughts? A 200-400 1.4 with 1Dx total like $17,000! Ouch.