Hoverla

24-105 f4 is superb on the 5dm2 , I do find that 24-70mm f2.8 on 5d is just too narrow dof to be usefull for anything narative with actors - so Im in the f4 - 5.6 region on a 5d for narative stuff so the dof is useful ,
I would go for the 24-105mm its a great lens is is very very useful for hand held run and gun stuff