I crushed France as Burgundy in my 1.8 game but noticed that Poland is really powerful. They formed Commonwealth and are keeping Moscovy at bay until 1600. Aragon is doing better than pre 1.8 as well.
That's my observation, too. France isn't weak by any means, but I see it outperform in a few game, underperform in a few games, but still maintain a strong enough presence that it fills its historical role. HAB/HRE is more consistently the outperformer in that part of the world.
Yeah. The first few observer games I ran, it looked like the were comparable to 1.7 (i.e., significantly underperforming, but retaining enough strength to fill their historical role, somewhat. Unfortunately, that doesn't appear to be the case. The underperformance is more pronounced and they're becoming a bit of the "sick man", just centuries too early, having never approached their zenith. The good news is that they don't really need to buff them. Just undo some of the nerfs from this and prior patches.
In my Byzantium run I saw France get slammed by Spain three times, each time they were only saved by my armies coming to help them.
French AI seems rather poor at fighting two-front wars.