I guess this thread is a bit old but this lens is awesome. I use it as my hand held lens for general photos.
It is the only 24-70 with Vibration Control and it has good glass.
My camera is a 5D MK III and I often use a 600EX flash even during the day.
DSLRs: Canon 5D Mk III, Canon 60D
Lenses: Canon 16-35 F/2.8L, Canon 70-200 F/4L, Canon 300 F/4L IS, Tamron 90 2.8 Macro, Tamron 24-70 DI VC, Sigma 35mm 1.4 DG
Flash: Canon 600 EX(2), Canon ST-E3-RT, Alien Bees B800