I enjoyed it, but it's a bit of a train wreck of schlock bad taste, hard-bitten military action, big boobs, torture and glibly written psychological damage. It's ostensibly a Dark Magical Girl show, but only on the surface. In practice, it's mostly just soldiers, terrorists, cynical governments ordering black ops and ultra-violence.
But with superpowered girls in frilly dresses.
Our heroine is Asuka, who helped save the world three years ago. There was an invasion of silly-looking giant monsters. Walking teddy bears, that kind of thing. However mankind was nearly annihilated and there were massive casualties, including more than half of the girls on what's now called the Magical Five. (Kurumi hates that name, saying that it's wrong that only the survivors are remembered. They should be called the Magical Eleven.)
What's more, Asuka got a field promotion to team leader and thus feels responsible for teammate deaths. She's got PTSD. These days, she's an ex-magical girl who's coldly, emotionlessly attending high school and refusing never-ending job offers from the military.
That's a strong premise. I can even forgive it for being almost entirely uninterested in the magical girl genre. This show would hardly change if you removed the supernatural elements and made everyone grizzled male ex-commandos. The girls don't even fight magically. They use guns, guns, more guns, knives, Indonesian karambits, grenade launchers, flamethrowers, machine guns, etc. There's the odd magical shield, etc. but anyone who pisses off Asuka can expect to get straightforwardly cut in half. The nearest it gets to being recognisably a magical girl show are the goofy magical monsters and the cutesy mascot animal "fairies".
Asuka I liked. She has issues and her sense of humour died on the battlefield, but she takes everything deadly seriously and the show has a certain amount of integrity when she's on screen.
Kurumi I also liked, sometimes. She's the show's trashiest, dumbest, most off-putting element, c.f. her torture scenes, but that also underlines her pathetic backstory and her desperate, yandere-level devotion to Asuka.
All that's good, sort of. Unfortunately, though...
1. The show thinks it's tackling PTSD, but it's all surface level. We never see anyone suffer it for long, or with any symptoms beyond vague, general ones. One character gets memory-wiped and then everything's okay again! Asuka gets over the horrors by jumping back into even more horror. (I can actually sort of buy this with her, though, since Asuka's characterisation is developed in far more detail than anyone else's.)
2. There's lots of torture. The good guys torture any baddies they capture, then (if they're girls) turn them into allies. Eh? Does not compute. I'm pretty sure it wouldn't work like that. Besides, what's the point of torture if they've got magical truth serum, as in ep.4? It's basically just the show having a hard-on for Jack Bauer in 24, with a side order of "Kurumi needs professional help".
3. There's international politics and a grubby, cynical worldview. In some ways, this fits. I admire the neatness of keeping the authorities out of the picture by having them cynically deciding that the terrorists' current hostage would be more useful dead. Subjects like child soldiers, though, get introduced without much depth.
4. The girls have big breasts and are mostly lesbians, which is liable to make them stalkers, gropers and/or mentally ill psychos. (Lesbians are common in anime, admittedly, since there's a segment of anime fandom that hates seeing male characters at all. This anime's level of predominance, though, has tipped over into "trashy".)
5. Apparently, the manga's even more extreme. It has severed heads in the post, prostitutes at work in a brothel and goblins raping schoolgirls. (You can tell where those scenes go in the anime, but here they're less explicit.)
Oh, and the show's not great-looking either. The art style and character designs are pretty simple.
Is this a good show? Actually, to be honest, I sort of like it. It's wallowing in macho military grimdark and being fairly shallow about some sensitive topics, but it's also quite fun. It's too dumb and action-packed to be depressing. Besides, I think Asuka holds it together. The show would look a lot better if it hadn't plunged off the "every kind of stupid" torture cliff with Kurumi. (Those scenes should be offensive, but... again, the show's too dumb and lurid for that.) It's got absolutely nothing to say about the magical girl genre, though.