not really
24-70 2.8 is about the same price as the 24-105 f/4 IS kit lens. Ill take the 2.8 for ANYTHING any day. DOF improvement, low light, improvement (coupled with teh impressive 5dmk2 ISO makes the need for a flash nonexistent in most cases i found)

I mean, its not a bad camera, again, unless you are in a portrait frame of mind, or a walkaround. For any types of sports, it sucks