I've heard talk about carbon building up on the valves and Ford saying they don't recommend any spray down the intake. Now this......

 

I don't see that helping much. From my experience the "coking" of the intake valve comes fro putting around all the time (like my wife would do if I bought one). Anyone that drives one of these new GDI(T)'s aggressively should never see this issue. You will see oil in the intake tract, but the fix mentioned above will take care of that!

I've see GDI cars with almost fully plugged intake ports behind the valve because of traditional driving habits (normal everyday driving), that never happened on traditional injection.