There is speculation about which are most commonly used super-telephoto zoom lenses so let's see what are the most popular for Canon users in CR.
By Canon's definition of a "Super Telephoto" only one Canon you listed qualifies.
The other Canon's are just "Telephoto Zoom". Possibly the common definition of "Super" some photogs use is different than Canon's.
Absolutely! The Nikon 200-500 is weak at 500mm - from many reviewers and from users I've met - and has slow AF. The Nikon 80-400 has fast AF but mediocre IQ. You need the new Nikon 500mm f/5.6 prime for good IQ and fast AF. The 100-400mm II is tack sharp across the frame at 400mm and has blisteringly fast AF. It helps keep me with Canon.On my last trip I was able to use a 200-500 nikon with a companion D850 at some point. The af seemed much slower than the canon 100-400 II; also in 500 mm they have to close the F a little for better clarity. The guide on the other hand used a nikon D500 with a sigma 150-600. Pesima quality of 500 mm up and AF just very bad. I think my 100-400 II is far superior to those lenses beyond what some reviewers say. Exactly the 100-400 II is the reason why I would not want to change brands
Same, would have been a vote for the Sigma 150-600mm C from me.It would have another vote - mine - if the poll wasn't closed.