vengence wrote in post #17812303
f/5.6 would offer a lot of AF advantages over a 6.3 counter part. That and the better consistency with canon vs third party AF would make this lens very attractive. Honestly though, canon wouldn't care if this lens cannibalized sales of the 100-400 ii, they want sales regardless of which lens it was. If it took a decent amount of sales back from tamron/sigma from their 150-600s then it would be worth the small cannibalization of the 100-400 ii. That being said, the 70-300: still finds a market despite the 100-400l ii, and I'm sure the 100-400L would still find a market despite the existance of a 200-600.
I bought the 70-300L after trying out both the 70-300 and the 100-400 II. I liked them both very much but the 70-300 is small enough to just go in the bag and be with me when an opportunity presents itself. The 100-400 is barely too large. If the price is good, I would not be surprised to find a 200-600 increasing sales of the 70-300 over the 100-400 in tandem with the 200-600 - except the 200-400 with the built in TC is really 200-600 and it's huge and costs $10,000. It's also f4 constant aperture.