A2 is right on the mark. Ever since the collapse of part of termainal 2 last year, CDG has set up a temporary concourse somewhere in France... When arriving one must take a bus - from I think Normandy to the terminal building. There you go through Passport control and then walk to the other terminal. One must go through security again to catch your connecting flight. We go to NCE all the time and while AMS is a better airport there are fewer flights - so CDG isn't bad... even if we miss one flight there is one like every hour.

Flying back through CDG is a much longer process - one has to walk a long way to make the connections and security.... and then the bus to the Loire valley for the flight home, at a temporary but pleasant little terminal........