dom33: AT over 3x the price, how much better than the 70-300 VRII can it be?
"AT over 3x the price, how much better than the 70-300 VRII can it be?"
Well, one thing's for sure - it'll be 100% better at f4 than any given maximum aperture on the 70-300, which starts at f4.5 on the short end. :)
On a more serious note, it's a constant aperture lens. You're PAYING (among other things) for a better performance at a given aperture. Like the fighter pilot community used to say, SPEED IS LIFE.