Sibil wrote in post #18566604
I wish I hadn't read that. I have been resisting it for the longest time, given that I already have the version 1, and the Tamron 150-600.
Having owned a Canon 400/5.6, Tamron 150-600 (1st version), Sigma 150-600 Sports and now the 100-400 II, the 100-400 II is without doubt the best lens in that category, by far. Tamron was the worst, Sigma was good from 150-400mm but it's a big lens and is front heavy when extended, and the Canon is super sharp, very light but no IS really hurts it.
That said, the 100-400II is crazy sharp for a zoom, very fast AF, 4 stops of IS, is quite light and small and best of all, plays very, very nicely with a 1.4x extender, so you can get up to 560mm f8 and it still focuses sharp and quick.