I know I'm a bit late with this, but I picked this up during the Summer Sale I just finished it.
What to say? I saw a couple of reviews complaining about the graphics, but aside from the uninteresting skyboxes and some stiff facial animation, it looks great. It's very depressing, with no really "good" ending, Sarif's I guess, but I guess that was the point. I enjoyed the characterizations, except for Jensen's continual "batman voice". It's very message heavy, without ever really beating you over the head with any one point of view.
On the whole, I'd give 4.5 out of 5 or 8 out of 10 or whatever. It's probably the most complete realization of a concept with very few hiccups that I've seen in a while.