I recently flew into and out of CDG. It is a large and confusing airport overall so give yourself extra time. I arrived and waited around 45 minutes to get through immigration. Next remembering a tip from the new RS Best of France Guidebook, I purchased my RER suburban train ticket at a Paris Tourisme office in the airport (no line at all and a person to talk to) rather than walking to the RER train entrance and waiting in another line at the ticket machine.
When leaving Paris for CDG I had a bit of trouble purchasing my RER ticket from the machine one floor below street level at Gare du Nord. A kindly French woman helped guide me through. Important, on another tip from the RS Guidebook, I had set up a PIN for my credit card prior to travel. The ticket machine asked for the PIN!!
My exit flight from CDG was on Aer Lingus to Dublin. If this is your flight out be there early and get in line as soon as Aer Lingus personnel begin stirring behind their ticket counter. I was there early but I didn't get in line immediately and I waited almost 1.5 hours in line as they slowly processed travelers to Dublin. Then I had to move quickly to get through immigration to the correct gate.
I then had a connecting flight from Dublin to Washington DC. If its your first time on this route be advised that you go through US style security in Dublin, as its the shoes that they can't live without scanning. Next US immigration is in Dublin which takes additional time. Sure hope you have sufficient time between flights.
This was my first time re-entering the US using Global Entry. It was very quick. The power of facial recognition technology is intimidating.