Hey Photographers! I need some advice. I just received my Z9 and its my first mirorless camera. I have 3 DSLR body camera and some F mounted lenses: 500mm F4, 300mm F2.8, 70-200 mm f2.8 and macro and wide angle. I am thinking to sell all my lenses and my DSLR except the 300 mm F2.8 and my D850. I am really interested in the new 400mm S F2.8 . I wanted to order it this week or when I am sure, that is the best lens choice I need. I travel a lot and it is big problem to carry everything in the plane and worry each time about it. I photograph every living thing from the tiny one to the big one. I love bird photography a lot. So can you advice me if I should go ahead and buy the 400mm or wait for the new 600mm? I know the 400mm would be more useful for big animals, but is it good for the tiny birds? I know we can use teleconverter, but I also want the best photo quality. Thanks for giving me your thought. It will help me a lot