well, what kind of environment do you shoot at the most, what is your budget.
will you break up your bank to buy 70200IS2 if not go for it, enjoy the extra stop of 2.8
if not 70200f4IS have the advantage of being light weight and much smaller then 2.8
- I myself shoot with 70200IS2, love it, but hate it.
love the results, love the image quality. but dislike the weight.
tho i didnt break my bank to buy it, but still need time to recover it
i tend to buy all the 大三元 because i need to 2.8 to shoot indoor, event and even at night time.