So I have a canon t2i and the EF-S 17-55. Its a great lens and I am happy with it. However I am thinking of getting the canon EF-S 10-22 because I like shooting landscapes and city-scapes. Now with these 2 lenses there is going to be a big overlap on focal length. So I am thinking of selling the 17-55 and getting a 24-70 (most likely tamron). The combo of 10-22 and 24-70 will cover all the focal range I want (I have a 100-400 for wildlife). So my question how is the 24-70 on a crop? Those who have used it did you find yourself wanting more on the shorter range?