Ok this is an improvement from the first season but still has the same problems that makes it not enjoyable, just like in the first one and that problem is Chidori and her constant unjustified violence and other considerable problems of interaction between Sousuke and Chidori.
Story
The story starts two months after the first season with a somehow changed enviroment, like if Chidori was more violent and isn't aware of the hard work Sousuke is put on by Mithril but for some reason she is bitchy towards him for not being there for her (he should be sorry for saving people) and when he is close to her she starts with her unjustified violence and that happens even in serious scenes where ''comedy'' is not required and i even thought she improved because of one particular ep. and therefore starting to understand Sousuke but when she reappears after what was a mature story with Sousuke as the protagonist, she blew my enjoyment, that enjoyment that could gave the anime a higher score, that enjoymen that i was having with an improved story, i was thinking that the story was much better without Chidori and just focused on Sousuke and the Mecha drama, it was a much better setting, what was the best is that Sousuke was finally asking himself what was he doing with his life? is that what he wants to keep doing? does he want to keep following orders even if he by following them couldn't protect Chidori? and i knew the story was more mature in the manga because i was spoiled that scene of what he did with that Chinese woman, it only surprised me that it wasn't adapted like it was in the manga, the thing is that Chidori ruined the story with her uncalled violence, but the story is good even with all that mess.
Art & Animation
The animation improved a lot, more smooth and much better in general, nothing to complain about it but yeah is very good considering it was from 2005.
Sound
Better music and it has the same VA but more concentrated to make a great job at doing the voices; The OP is kind of like in the first season skippable and the ED was odd, it has something that made me think it was sad for some reason, it's crazy considering the clip is Sousuke and Chidori walking but with a maybe normal ED song, i don't know just that in general it's very good.
Character
A more improved cast of good characters but is not enough to consider the characters the strong point of the anime because if it has a particular character improvement like Sousuke then we are presented with Chidori and her same attitude, for some reason they act different, what happened in the gap time of two months from first season and second raid because is not explained why Chidori has Alzheimer with Sousuke and what he does in his daily life and why Sousuke acts like a douche with Tessa and Tessa's character was another problem, she was one of the few that i liked in the first season and now she is like almost not there and why would Sousuke say she's important to him but he doesn't show it, it's a mess, i liked that Chidori was missing Sousuke and acting like him when he was not around in one particular ep. and i thought that she was finally going to understand him and his protective persona and at that point for some reason i didn't hated her but when she finally reunites with him like i pointed before she blew it with her stupidity again, i was trying to find the reason on why she used violence with him, i can't even... The Xia twins were interesting but it wasn't enough, i wanted more of them and it was obvious who their master was when that Gates guy mocked their master and of course Melissa and Kurz are the same.
Enjoyment
Like i stated the enjoyment is good and even more if people don't mind a character like Chidori, not her character as the whole problem but her attitude, i can't stand that kind of character with unjustified violence and not that i don't like Tsunderes because i do but that is one of those cases that are annoying and not enjoyable at all because that ''comedy'' is not comedy for me.
