Have an older 100-400 L 1 lens. Did the MFA on it to bring in the focus. The lens has been giving me so many great photos. Next week I hope to pick up the newer 100-400 L 2 lens. Cant wait.
I may be wrong, but I think you'll really be surprised at how much you like the new 100-400. When you run it on your 7DII...it's almost like they were made for each other. The speed at which it sharpens, and the image quality you get will put a big grin on your face. Have fun!