I just did a shoot with the 7D and I used the EF-S 17-55 2.8 IS and the 70-200 2.8 IS. They both preformed amazingly. Having a zoom lens helps the speed of set up tremendously. It’s much easier to turn the lens ring rather than move you’re whole rig forward of back.
Important to understand that while true, the 17-55 is a shortback and thus not for full frames, the 7D isn’t full framed either. (APS-C) Now having said that the 17-55mm focal lengths will actually be correct. Unlike the 1.6 multiplication needed to factor the actual focal lengths of standard EF lenses. Simply put 17-55 is ACTUALLY 17-55 and not 27-88.
Travis