+100 with Stein
I am mostly shooting birds while actively birdwatching (not sitting in a blind with a tripod for hours).
I don't need/want a zoom, I have no use for a 400/500/600 weighing more than 1,5kg, price being irrelevant.
I want a 400/5,6 IS I can carry around while running around using my binoculars and carrying my spotting scope.
The only option right now is the 400/5,6 (no IS, old lens) or the 300/4 IS (loss in IQ, old IS)….
So I think the 400/5,6 IS is overdue :-))))
I am over 70 and can handle the 100-400mm with ease for hiking for hours, and now my wife is doing so as well. How old are you? 80 or 90? Or, maybe, 100?