initial impression compared to my sigma 70-200 apo hsm
1) IS is wonderful. I can handhold 1/20sec at 200mm and have a good keeper rate.
When I sit in a chair, I can even get 50% keeper rate or higher , shooting 1/6sec at 200mm, insane.
With the sigma in my office, I have to use ISO 1600 or even 3200 for 200mm, even at f/2.8 coz the shutter speeed has to be at least 1/200sec. Now with the IS II, I can shoot 1/6sec , with ISO 50 , that's nuts. Not to mention the sharpness difference.
2) 200mm f/2.8 has about the same sharpness as the sigma at f/5.0, in another word, much sharper than sigma at f/2.8. The sigma is pretty good between 70~150mm, but weaker at 200mm.
3) AF is super fast, but the sigma isn't bad either.
can't wait to bring it to field test!