While IS is great for up to 3 stops of exposure to prevent camera shake, it isn't going to freeze motion.

I am not knocking the 24-105 at all, but the way I see it the F2.8 outweighs the benefit of IS - it lets you go up to a shutter speeds where camera shake shouldn't be an issue (especially in the 24-70mm focal length range) and is pin sharp at that aperture.

It would have meant a noisier ISO setting and careful attention to technique to avoid camera shake.

I put it on my camera and drained the battery in a hour b/c i could not stop shooting random things around the house.

, I think the nod goes to the 24-70.Next, the extra reach (to 105mm on a full frame or 168mm equivalent on an APS-C like the 40D, 50D, Rebels).

It is built like a tank, and I have taken it to the base of Niagara Falls (as wet as that is) with no issue whatsoever

The other functions of lens work as they should and everything is tight, down to the lens hood

or it's jut not as sharp as it sould be, specially for the price!

This immediately made me wonder as to why the broken parts were not discovered the first time Canon serviced, and why did the focus ring become loose

When I received my 24-70 f/2.8 lens, I was ecstatic to find that the results from my new L Glass zoom were every bit as impressive as from my prime lens.

F2.8 is not as sharp as the Canon 70-200 F2.8L but it is still way better than anything from other brands

It is built like a tank, and I have taken it to the base of Niagara Falls (as wet as that is) with no issue whatsoever

The other functions of lens work as they should and everything is tight, down to the lens hood

or it's jut not as sharp as it sould be, specially for the price!

This immediately made me wonder as to why the broken parts were not discovered the first time Canon serviced, and why did the focus ring become loose

When I received my 24-70 f/2.8 lens, I was ecstatic to find that the results from my new L Glass zoom were every bit as impressive as from my prime lens.

F2.8 is not as sharp as the Canon 70-200 F2.8L but it is still way better than anything from other brands

L Lens looks like it ate my EF-S 17-85mm.

I like the versatility of my EF-S 17-85, but not happy with the ave colors or medium contrast or low end distortions

It is built like a tank, and I have taken it to the base of Niagara Falls (as wet as that is) with no issue whatsoever

The other functions of lens work as they should and everything is tight, down to the lens hood

or it's jut not as sharp as it sould be, specially for the price!

This immediately made me wonder as to why the broken parts were not discovered the first time Canon serviced, and why did the focus ring become loose

When I received my 24-70 f/2.8 lens, I was ecstatic to find that the results from my new L Glass zoom were every bit as impressive as from my prime lens.

F2.8 is not as sharp as the Canon 70-200 F2.8L but it is still way better than anything from other brands