I haven't read 7 yet but I've read the other 6.
I think it's a pretty good comic and Ennis does his usual stuff: extreme sex and violence. I reminds me a little of Mark Millar's Wanted with the subject matter (I said reminds me, not is like. Just incase people give out shit with my comparison).
I also sort of get the "next Preacher" vibe from this book, more than some of his other pieces of work and when it gets thrown around. Like, while it's not the best book I've ever read, I've a feeling in about 2-3 years time everyone will be going on about how great it is and cutting edge etc.