I presume you've started hitting the gym already or have a couple of Sherpas at hand? The lens is awesome but it kills you with its weight if you need to shoot handheld
Why not get the 500 / 600mm f.4?
I can always spend some money on monopod
I shoot indoor alot, therefore, f2.8 is more important to me than lenght. I can always add x1.4 or x2 TC if needed.
shooting 400mm indoors a lot?
Maybe I'm missing something.
5D3, 6D, 600D, RX100
16-35L, 24-70L II, 70-200L II, 100-400L, 50L, 85L II, 135L, 24TSE, 40, 100 macro, 18-55 II, 55-250 II, 600RT x 4
I come here to learn something new, not to learn how bad my gear is - I know that already ;-)!