This is intended to people that watched the first season, and if you didn't yet then you shouldn't be here, as this season is chronologically next to the first one, and you won't understand this universe if you start with this one season first.
First of all, if you already watched season 1 and you liked it, at least for a 7 out of 10, then you will enjoy this second season. Watch it, it's not a waste of your time.
But I want to be fair, so I will organize this review in two sections: what is better done than the previous season, and what is done worse.
The following paragraphs may contain spoilers or clues that may ruin the show for some, so please, do not continue if you are "spoiler vulnerable".
--- Done wrong ---
- The worst is the peace -
This one hurts me the most of all, all other are forgivable details. The first season has a nice peace. Story unrolls considerably fast. In comparison with most animes you don't have to wait to much for something interesting to happen. This second chapter is still tolerable, there are worse animes, but it's sad that sharing the same title it doesn't share the same quality.
They included that action scenes right in the beginning because they need to maintain the public watching somehow. Shameful. And please, before answering to this, I beg you to try to be objective. We are more tolerable with second parts because we already love the characters, I cannot explain in another way why some full of fillers anime like One Peace, Naruto, and others super lengthly shounen are at the top.
In my opinion, you have to wait too much for something interesting to happen for a only 6 episode show.
- Less Yuri -
And is not that the original has any yuri/shoujo ai in it. But for the ones that like to fantasize with this it's annoying that in the second season you find it harder to do.
--- Done right ---
- Even more girls -
For a "404 men not found" show, that you will only get from Japan (Americans would feel too gay doing this), more is always better. I personally liked the fact that a character that was so charming, but so done for, in the original is now all healthy and sharing screen time with the other girls. She is a blonde, wow.
- The bogus hero system was fixed -
Second seasons are to do things differently. It is boring when they are too afraid of try new concepts.
Now, the value on this is not only that they had the courage to change things. It actually has sense. If the girls proved that the hero system can works in a different way, of-course this has to have some kind of impact. So, the new hero system is not based any more on sacrifices... well, at least not in the same way.
- They stay on topic -
And for a 6 episodes show would be weird not to. The first season started with a ton of generic fights. I took it like a generic anime made of unrelated episodes, like most "for kids" shows. I stayed because of the cute characters and the fights special effects. But it didn't lasted, with things getting truly interesting when Togo discovered her imposed invulnerability. Then, and it's noticeably the similarity with Madoka, things changed from funny to very serious in just an scene, and it stayed serious till the end. I may like the original so much because of that sole moment.
But this installment hasn't generic fights. It stays on topic from the beginning. Suffering of the girls still escalates with each episode. Slower, of-course.
--- Conclusion ---
If you watched the first, you will watch this one. It doesn't really matter what reviews you read. It is a common feeling, when we finish one of these shows, that we didn't get enough of the characters. So continuations are rarely unwelcome. I tried to be objective and not centered only on the good.
I can't give this more than 8. I wanted to give it at least one less than I gave to the previous installment, but in the end I decided to give it an 8. Note that I gave this one only a 6 in story.