Good choice. That is what I have. By world standards, it is not great btw but it is the best wide angle for a full frame canon camera that interfaces with it. Better quality comes from mod'ing medium format lenses, causing you to lose all automation.
Have it. Not a fan. Mine gets next to zero use. It is quite large and heavy. Produces really good images. However, it has a pretty short range and no image stabilization. I much prefer the 24-105 F4IS. The image quality might be a tad lower but it is so much more flexible lens that you will take tons more shots with it. You go from landscapes to portraits in one shot. With the 24-70 you will be changing lenses all the time to cover this range.
One of the best zooms Canon makes. Wonderful quality. Unfortunately, it is huge and heavy. Mine stays home most of the time. Only time it goes with me is if I am shooting low light situations like my sons graduation. Otherwise, my pick would be the cheaper, and even slightly better quality 70-200 F4 IS. This is a much, much lighter lens, and smaller to boot. It puts a smile on my face every time I use it.
I have the Mark I. Mark II is a bit faster but it is still dog slow to focus. Worse yet, it has an electronic focus ring ("drive by wire") which is totally unnatural to use in manual mode. You will not be able to capture hardly anything in motion with it. Of course, it is extremely bright and practically "makes light." Background blur is as dreamy as it can get. Best to think of this lens as a specialty lens, mostly for portraits. But if this is the application, I suggest the 135F2. It doesn't have any of the negatives of 85f1.2 and its image quality is amazing. Another, much cheaper alternative is 50f1.4. It is tiny, tiny, tiny. And it is cheap. I carry one in my pocket all the time. It is too wide though for general portrait work.
On trips, I take the following with the percentage of shots from each:
24-105: 70%
70-200F4: 25%
50: 5%
So yes, there are times you need the longer reach to create a nice background blur, isolate subjects, etc. If you are not sure though, that is more of a reason to get the F4 version of 70-200. That way, you can see how much you use it and how much you miss the extra brightness. If you do need the f2.8, then you can reserve the f4 for travel as I do. There is no way you would want to lug the f2.8 around on family outings.
