I finally managed to finish this book and overall I loved it.
I actually think the best part of the book was the first third with all the great character work, scheming and rising tension.
When the Aliens escape, it kind of descends into an above average Alien novel.
While Dorian turning more and more villainous was interesting, I think it could have worked in reverse as well. I mean him actually turning into a decent person with all the hardship. Him starting to bite people at the end was a bit over the top.
Some questions left open:
What happened to the sentry guns? They are set up as a great way to contain the Aliens and never mentioned again later.
Why not use the escape pods immediately? I know most of them were destroyed later but just look at A:R with an efficient way to evacuate.