I don't live in France and I haven't been on the MP14s, but two things that I'm not a fan of is the seating in the very front/rear of the train and the positioning of the information screens within the car.
For the seating, the blue seats that have 3 and 3 facing each other have very tight legroom and no standing space compared to the MP89s and MP05s. I guess whatever components they have against the walls that cause the seats to go that far into the center of the car is causing that, but in my opinion, those components should've been installed in other locations to provide as much space in the car as possible.
For the information screens, there are 4 screens in each car, but they are placed completely symmetric across from each other. If you break the car down into 4 parts, they are placed in the 1st quartile (near the bellow) and in the 3rd quartile (over the door/orange seats on the opposite end of the car) depending on the direction the car. Would've been nice if on the left side of the car, the screens could be in the 1st and 3rd quartiles, and on the right side of the car; the screens in the 2nd and 4th quartiles, so the displays can be staggered and allow more people to read it no matter where they are standing in the car. This set up limits who can see the information screens within the car. On the Northern section of the train, the screens closer to the bellows are on the south side of the car, and on the southern section of the train, the screens closer to the bellows are on the north side of the car. If anyone has been observant enough, they would notice that the cars are in a 5x3 configuration rather than a 4x4 configuration, so the 5th car in the Saint Lazare direction / 4th car in the Olympiades direction should be turned around for symmetric purposes. The first and last cars have exceptions in seating arrangements/screens for ADA reasons, and therefore a screen is placed on the window opposite of the ADA section.
Nonetheless, it's a beautiful train, just those two complaints should've been more thought out in my opinion, especially the seating arrangements.