Cathy, if I were you I would go for 24-70 without any hesitation. Your wide end has been taken care of with your 10-22, and you will have a 70-200 to come. So basically what you need is the coverage for mid-range. Both 17-55 and 24-70 perform great optically. Paying some extra for the build quality of the 24-70 worth every penny you'd spend.


As I just went through the same choice-making process and I have ended up with 24-70, I can say I am happy with it!


Hope this helps!