For a basic everyday lens for a Canon 5D, I'm considering the EF 24-70mm f/2.8L USM and the EF 24-105mm f/4L IS USM. I do mainly outdoor and landscape shots, but also want the capability to shoot indoors w/o flash. I've been told by a professional that he uses the 24-105 because he likes that extra 35mm so that he doesn't have to go to a long lens just for a shot here and there. He feels that the IS on the 24-105 makes up for the faster 24-70, taking it down two stops to be equivalent to the latter. He does mainly indoor events. I plan to get either a 70-200 or a 100-400, depending on which of the above I choose as the basic lens. Any suggestions? Thanks.