After "Iriya no Sora, UFO no Natsu," I sort of became a fan of Akiyama-sensei, so despite having many other backlogs, I bought this and even read it before the others. Now, I can say that I am a fan of Akiyama-sensei, and I don't need any qualifications like "sort of." I love his way of "engineering" the story format. His themes also jibe well with me, even when I don't necessarily agree with some of them.
This is pretty much completely different from the anime. Sure the main character, Haruka, and her closest five robot friends are the same in both stories, but that's about all the similarities.
Anime had many little focuses, such as war, parenthood, overcoming traumatic experiences, etc. Now that I think back about it, it had a lot of standard-fare themes in it. I certainly didn't think it was bad, but it just wasn't especially good at anything particular.
This original work has much sharper focus on just one theme, although I can't quite put my finger on it yet since I've only read about half of the whole thing so far, but to give you a hint, it's "canine." "Huh?" you say? Well, that's too bad.
I may or may not write more details on the second volume listing. At the moment, I'm having an internal conflict reading the second volume. Part of me wants to know what happens next while another part of me is afraid of learning what might happen. Needless to say, it's very interesting.