I got the T6 French BB, and oh boy, she has the WORST dispersion, period. Every other T6, STOCK, has better dispersion, and this is with a fully upgraded Normandie. I really prefer Bretagne over Normandie, because her dispersion is much better. But, Normandie is quick off the line (for a BB), and has very good maneuverability. She feels average when it comes to tanking and while she has a lot of secondaries, they are not as accurate as I was expecting.
One thing I'm finding about the French AP shells are, they overpen, a LOT.....on EVERYTHING. I ended up flanking the Izzy in Newport with Normandie, at 12k and closing, I kept overpenning. Her dispersion is so bad, that even at sub 8k I had trouble hitting Izzy's citadel, and hits I did land, overpenned. I decided to use HE in my next run and saw better results overall, but French HE is meh. Least the damage was more consistent. This applies to Bretagne as well, but not as bad. Her AP is more reliable.