As you'd expect from Shouji Sato if you've read any of his other works, probably the first thing you'll notice is the series features a lot of characters with big boobs and a ton of fanservice. If you can get past that (or even better, embrace it) then you have a pretty awesome action pulp manga here. The story is implausible in so many ways and seems like something out of a sensational drive-in movie or something (An invincible death-squad that works for a hospital! A main character whose body is made up of the parts of his dead friend! A 14 year old pop star bomb enthusiast who also does softcore porn!), but it's all good because rather than feeling stupid or contrived, it's just ridiculous enough to be awesome. That's the name of the game here. No life lessons, no meaningful philosophy, just cool, well-flowing action and kills with an occasional one-liner. Oh, and boobs. Lots of boobs. The story may seem a little mindless but it's really entertaining and I love the ideas behind it.
There are a lot of characters but thankfully they all actually get a lot of screen time and the dialogue is distributed quite well. You may have a hard time remembering all the names, but the characters are distinct from each other and you can tell them apart with a simple description. The Big-Boob Doctor, The Old Sick Dude, The Nurse who Dual-Wields Machine Guns, The Foul-Mouthed Bitch, etc. If you've read the first chapter you probably know exactly who each of those characters is.
The art is Shouji Sato's usual exaggerated proportions and ridiculously detailed weapons and vehicles. I have nothing to complain about here. The art is definitely high tier stuff, though SS' character designs may not "work" for everybody.
The only serious problem with the series: it moves a bit slow. The art is huge and takes up a ton of space, so there's not a lot of dialogue on most pages and it actually took a while to establish the story in the beginning (I don't think things were adequately explained until chapter 4 after two missions had already taken place). For comparison, Fire Fire Fire, which was bimonthly, had very good pacing and wrapped enough things up each chapter to leave me satisfied while still wanting more. Here, arcs feel a little drawn out and although I'm usually left wanting more, individual chapters don't always feel satisfying. If you read the series in volumes rather than in chapters then the pacing isn't a big problem, but the monthly releases can be painful.
Okay, so basically in conclusion, this series is total pulp. It's not trying to be art, and it knows exactly what it is: it's a ton of badass sexy gals (plus one guy) killing evil dudes and blowing stuff up and taking showers. It doesn't skimp on the violence and nudity, and it's all the better for it. If I had to sum the series up, I'd say this is the manga equivalent of an awesome action movie. If all you want is a good time, then I think this will be just what you're looking for. Check it out!