The whole Lockon thing was spoiled to me already, but it was a cheap way to bring him back. I don't think it was a bad thing in overall, but when you look back at it, it feel kinda stupid.
Actually, many parts feel scripted when you stop and take an objective look. Drama is nice, but is it really possible to be less lucky with the match up? No matter where they are, they always meet up agaisnt their nemesis. Because of this, you lose the impression they are actually fighting against the world.
Some character were completely wasted too. Graham had a really good introduction in the first season, but everything was trashed in season 2. He piled every possible stereotype, and managed to have absolutely no impact on anything. It's a shame, because I thought he would be one of my favorite recuring character early.
Wang liu mei, Nena and a few other were also wasted. Some of them served their purpose, but in the end, they could have been a little more useful to the story. They just did their thing and died. I supose not everyone can get their "sad" death scene...but it was just unrewarding in this case.
Oh well, there was many good things to make up for this. I loved what they did with Louise character, it was unexpected (kinda..you knew something would happen with her). Saji..not so much, even if it was ok (thank god he wasnt the main character though). Setsuna was interesting for a lead character. You expect him to change and become emo, but he is constant through the whole show.
Smirnov/Marie/Allelujah were my favorite for sure. I liked them right away, and their story kept my interest through the whole show. I'm actually surprised Marie survived this long...especially after getting a "good end" around ep 12. And Allelujah keeping both personality was unexpected as well. You expect something bad to happen...but it never come.
I hope they are not saving it for the movie thought >_>