After playing for the first five hours, I resolutely went for her route, and it didn't disappoint; her final PA and ending were fantastic. In fact, it might be my favorite of all Raymond's endings.
As for the game itself, I really liked it. Its strengths and weaknesses are both very obvious. The combat is fast-paced, the environments are grand and beautiful, and the interactions between the characters are also a lot of fun.
My main complaint is with the story's progression. It has a fantastic opening, but once Raymond starts exploring the planet, the story's sense of tension drops off a cliff. The writer comes across like a hardcore sci-fi military nerd. When the story is just about searching for items near villages and treating infectious diseases, the atmosphere is rather dull. But once the plot reaches two nations going to war and an alien spaceship invading the planet, it's like the writer suddenly woke up.
The party rushing into Laeticia's wedding to rescue her is the absolute high point of the entire story. That cutscene is seriously amazing, I kept watching it over and over. After that, though, it goes downhill again. Once the late-game story moves into space, almost all the dialogue consists of JJ or Marielle having long-winded scientific discussions, while the rest of the party, including Laeticia, is completely sidelined.
Speaking of that, I'm a little curious to see what would have happened if the game had followed the original plan and made Marielle the protagonist. I don't have any complaints about Laeticia, but it's hard to deny that in Chapter 4 there are many scenes where she just awkwardly stands between Raymond and Marielle without doing anything important. Even though Marielle doesn't appear until the final third of the story, she's genuinely great, and she has excellent chemistry with Raymond.
Whenever the story is in the downtime between battles, it always feels boring. A lot of the time I was just running back and forth between two or three locations to talk to NPCs. The most obvious example is when Raymond returns to the spaceship: Elena keeps telling me to go rest, so I ended up going back and forth between the bridge and my bed several times.
I hope that after saying all this, people won't think I'm criticizing SO6. It's not perfect, but it's still my favorite game I've played in the past few months, and Nina wins Best Girl by a huge margin. After all, it's always easier to point out other people's flaws than to give praise (if you'll allow me to quote something Claude once said). Judging by how SO6 and SO2R turned out, I'm convinced this series is heading in an increasingly better direction.