I see no reason to either be excited or care about Canon lens releases anymore. With Nikon taking the lead in inflated pricing with the 80-400mm by charging a mind-blowing $2700, Canon is certain to do the same.
Since upgrading to FF, I've bought and returned a 24-70 F4 IS and a 35mm IS. I bet you can guess what I went with instead I have also scrapped plans to buy the 70-200mm F2.8 IS L v2, targeting the Tamron F2.8 VC instead.
The days where Canon and Nikon could command massive margins over 3rd party due to higher quality are gone. H*ll, they can't even get rebates right. That last round increased pricing on half the items.
so what other 100-400mm lens you have in mind....
it´s great when you have alternatives... no question.
but i don´t really see one for the 100-400mm, do you?
sigma? not the existing sigma lenses. nah.. sorry.