I have the 50D and the EF-S 17-55mm f/2.8 IS and a B+W MRC UV Filter 010 filter and it is my main shooter. I took 176 pictures inside church of my son's First Communion yesterday and 174 were keepers and 175 would have been except I took a picture of a girl who was not part of his class and did not need it. Mind you I was shooting with no flash. I highly recommend this combination if you are not able to use a flash and/or need to freeze motion. If or when I move to a full frame, I will most likely keep this as a second camera or I am sure with the way I care for it I will be able to sell it for a fair price taking into consideration all the memories I will have captured.