Either mad props or best of luck to you. I bought my first 1Dx 13 months ago, and I don't know the AF system 100% yet, nor am I disciplined enough to go into the menus as conditions change and make adjustments (let alone the RIGHT adjustments). I know it's tough to leave a new camera at home, but do consider going with what you know, as the new toy might give you some surprises your clients won't like.