(With apologies if this is a subject already covered elsewhere; a search turned up nothing, but that could be user error. If there's another thread, please link me to it.)
I've got the 400L and am considering adding to it or replacing it with the Tamron 150-600. My telephotography is exclusively wildlife, and of that primarily birds. I use the 7D.
Just wondering---anyone out there have (or had) both lenses? How do they compare?---and by that I mean in sharpness wide-open, in light-neediness, in focus acquisition and tracking, in hand-holdability, and in keeper-rate.
I know my style--if I got the 600, I'd be shooting at 600mm 99% of the time, and I'd hope to be able to stay wide open in the aperture.
Any thoughts welcome!