I own both the EF-S 10-22 and the EF 24-105L. The 24-105 remains on my camera 90% of the time, but it does leave a little to be desired at the wide end though. The 10-22 fills that void perfectly. It's the closest you can get to feeling like you have a full-framer. The exaggerated perspective and FOV is incredible. It's such a fun lens. I was also considering the 17-40 because I anticpate upgrading to a full frame body at some point. The difference between 10mm (107 degrees FOV) and 17mm (77 degrees FOV) is light years apart. If I am shooting landscapes the 10-22 is always with me. I have been very satisfied with its sharpness and would buy it again.