No question about it. You need this picture style if you shoot on the 5D. Best to focus and expose in Canon’s Neutral setting then switch over to Technicolor’s CineStyle just before you hit record. You’ll have the latitude you need to color grade since the 5D is actually pretty contrasty.
CineStyle definitely has a softer look which makes for a more difficult time when trying to focus, hence the need to focus in the Neutral setting. The trick is to remember to switch back and forth as you go.