I’ve been shooting with this lens for a year and a half, before that I had sigma 18-35 1.8, but I broke up with it because of unpredictable autofocus, which also freezes in the cold. And the Canon 17-55 2,8 is the best universal lens for the EF-S mount, even despite the significant disadvantages. The picture gives a wonderful, universal focal length, the stabilizer sometimes helps out. Therefore, as long as there is 7D, I will use it.