I currently own a 70-300L which I bought to take with me on safari. I used to have a 70-200/F2.8 IS II but sold it mainly because I didn't use it all that much on my 7D. Mostly due to the size/weight. I did love the images of the 2.8 though (duh).
Recently I bought myself a 5D Mark III and now I'm very much in doubt to get the 70-200/F2.8 again. Size will still be an 'issue' but I know the 70-200 focal length will be a lot more useable on my FF for indoor shots/portraits. I sometimes do paid work in churches like weddings, so for that the 2.8 can't be beat.
On the other hand, I currently own the 70-300L which is optically VERY good. Have used it on my FF a couple times now and I'm very happy with its picture qualities. Only thing being a little of a letdown is the aperture, especially when I will be needing this one indoors for those low light shots.
There's a large rebate on the 70-200/F2.8 coming in a few days here in Belgium, so I'm very much in doubt. Anyone had to make the same decision, one way or the other? What was your experience. Right now I'm a little bit leaning towards keeping it, and just seeing how it'll perform in low light because the 5D has made using larger ISO's a lot more viable so maybe it'll perform ok enough.

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