yeah... real photographers do wear those things.
Missing shots:
that's unfortunate because I do all the things you mention and Im gonna use a 70-300 IS non-DO more and more often. For news in particular. Not really because of the size (I shoot 1Ds go figure how much I care about it) but because I like the pictures: they are fresh, candid, naive. I love them.
The 100-400 again is white but it takes more or less the same pictures.
The same for weddings. Nice close-ups from the distance with not too much bokeh. Perfect.
I guess that Im doing it all wrong then..
oh well...
so, basically if we take the stealth thing away (as I understood you don't use the DO because of that), then the only advantage will be the size as long as it's not extended. Size to fit into a vest or a bag. But it's larger than the non-DO: so size counts up to a certain point. It's also heavier but still better because... it fits into a vest. I fit into a black shiny domke vest the 100-400: does it make the lens good in terms of fitting the vest thing? I guess so. Does the 100-400 take better pictures of both the Do and non-DO? not really. But at least it goes up to 400 (well, I did find something to justify the white push-pull one)
In the end I see the clear advantages of the DO: better something (not really the pictures) but something.. unspecified but I swear! if I keep thinking of it I'll find something.
This is becoming interesting, it makes me smile, but really.
Canon marketing didn't even get to that level: to justify a model just because... they should hire many in here to cover that job.