DoF can be with an 800 if you want to blur a close in background and I much prefer the in camera to Photoshop version.
And unless you are shooting in excellent light, with an F11 you are getting into an area where ISO is likely to be higher than you wish when using shutter speed high enough to avoid subject motion blur of anything but a statue. My 1DX III will take what I would call usable photos at 51,200 but I would much rather have it at half that ISO and even with its excellent ISO performance being able to shoot at a lower ISO with less amplification and resultant noise the better. Going from 400 to 800 ISO doesn't bother me but given 12,800 vs 25,600 even with very good modern sensors you are still giving up a lot of quality.
Canon will be able to sell many more of these slower glass long telephotos than they could the EF L versions because they will be far less expensive, large, and heavy. This could be the emerging market strategy from Canon in trying to secure the leadership position in the market above the "good" consumer level but beneath the top end and that could be smart positioning for the future. The lower end cameras are the ones most subject to being cannibalized by digital devices and the upper end market will become smaller volume but still important as a development bed and halo product area for the camera line.
Rodger
EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video
