I am aware that the wide angle is somewhat reduced on the APS type camera such as the Canon Rebel Xti (what I use) as opposed to the full-frame. However, I want to purchase a wide angle lens and am hesitant to get the 10-22mm since it is EF-S only ... I don't anticipate upgrading to a full-frame camera now, but sometime in the future (5+ years), I probably will. Does anyone shoot with an APS sensor camera and the Canon 17-40mm? Do you like it, and still get wide angle performance? I am on the fence about which to purchase, especially since they are nearly identical price-wise right now.