Well it wasn't really an option for me to buy the 24-70. And to be honest, I would pick the 17-55 over the 24-70 on a crop body any given day. There is really nothing to say about the image quality the 17-55 produces, it's just great!


My friend bought the 24-70 on his 50D, but he suffered a lot more chromatic aberation than I had with my 17-55. Same shots!


And the IS makes a lot of photos very easy as well. As well does the weight by the way. The 24-70 is really a big fat boy [:P]


I believe the 24-70 is build for a full-frame camera and therefor it's noticeably better there than it is on a crop camera.


Unless you need the ruggedness I would advice the 17-55.