My reactions were a little mixed:
1 - liked the tone and feel and the sense of something a little more genuinely 'mature'
2 - the dialogue was okay but not quite as good as I'd hope. However the demo is two 'scenes' out of context so in normal flow it might be better
3 - the graphics very very good and convincing, certainly 'up there' for what they convey
4 - the different choices flow well (trying a few different paths) with little sense of the normal 'puase' that takes place in titles like this (for example in ME characters 'snapping' from one animation to another to respond to your choice). However, the actual delivery of some lines contained odd pauses for no apparent reason, go figure
5 - the flow of action depending on the QTE respond was very good, with no sense of the animation jumping to keep up with whether you hit or miss
6 - on the other hand, I just don't like the QTE approach. During the fight I never felt I got to watch the actual visual event because I was so carefully watching for my QTE prompt. I remain very negative on QTE as an input (everywhere, hating it in GoW and other titles for the same reason) and feel a better control scheme must be possible while having this type of experience
7 - I did like an actual investigation (albeit brief) where it felt like I was investigating rather than the usual pointless hand holding in every other title with any similar element I've played (such as Condemned). Here I felt like it was up to me to look around and actually find stuff (or not) depending upon my own desire to do so.
So all in all I'm interested, and will definitely get the game, but I'm really not sold on the QTE input method.
Try to be reasonable... its easier than you think...