The new EF 200-400 is definitely no walk around lens, very heavy and expensive.
Who needs such a lens?
Don´t waste your money and use one of the big Canon telephoto lenses instead.
For travelling I wait for a new 100-400 lens.
Who needs such a lens?
I don't know, who needs a macro lens? Instead of macro people should just be happy with mid range zoom.
who needs long prime glass anyway? Instead go use a wide ange.
Need a wedding lens? I recommend you shoot without a lens...
This lens will have a great following and for many it will be a great consolidation of focal lengths. Sport photographers, nature photographers and traveling photographers just to name a few.
I know that I would happily give up my big glass for this lens if the IQ is just as good. I do a ton of wildlife photography and hike to access most of it. Currently I carry in an old 600 f4 and a 3002.8. I also shoot from a kayak and carry 2 bodies with long and short glass. I also travel and hate having to choose which lenses to fly with.
Well, maybe you are right. Who needs this lens anyway, maybe i'm the only one who could benefit from this lens.... Stupid canon...