I just completed the demo and the people here saying the demo made them decide to pass on the game are lying or crazy...
I agree the control scheme is very clunky and outdated; especially considering the number of enemies they throw at you. In some ways the controls make the experience more hectic, because you are trying to move around and fumble with different weapons, reloading, etc.
I'm not sure if some of that is by design to make the game have a more thriller type experience, but it can be frustrating. I would not say the controls are bad enough to say the game is "broken". Once I actually got the quick turn and run moves down I was able to get around ok...
The AI for Sheva is not the best, but it is adequate compared to other games. Also, I like how you can swap weapons, ammo & health. There was a few times she through me some ammo or did something helpful so it's definitely not terrible, but could use some work. Also more ingame banter between the characters would have added to the since of immersion and a bond with the AI partner. I do have to admit I will do my best to play the game on co-op, because it's a much better experience.
Also, I like the fact you get just enough ammo to get by so you are always worried you are going to run out and this raises the anxiety level during play through. I agree that some QTE with the mini bosses may have been a good move, but it's a gameplay mechanic that has been somewhat overused nowadays.
Finally let me talk about the visuals, because the game looks amazing on my 52" 1080P display! This is the best looking multiplatform next-gen title released to date... I really get that next-gen feeling while playing the game from a visual/presentation standpoint. I have the feeling 2009 is going to really show what these consoles can do.
I agree with others regarding the control scheme needing some work, because it's a bit antiquated by today's standards, but you would be a fool to pass up on this title.