Although I haven't made the purchase yet, I too have chosen the 24-70. This does not mean that I would necessarily recommend it for everyone, however I can share how I arrived at the conclusion:


On several occasions when I used my 18-55 kit-lens I consciously limited myself to the 24+ zoom range. Although I'm on a crop camera, this never was a limitation for the pictures I'm currently shooting, however I felt constantly limited at the long end => 24-70 zoom range is fine for me and my 500D.


While the IS on the 17-55 might come in handy in some situations, one of my everyday in-door photo subjects is my daughter of three years, as anybody with kids can confirm the anti-thesis of an unmoving subject => won't miss the IS on at least one of my main subjects.


Regards, Colin