Couple of things:
For one thing, at least the PS3 version isn't TERRIBLY unpolished, I've only encountered one in-action slowdown and that was in the train station in Russia at one particular spot if you run. Other than that, only some slowdowns during the cutscenes in the tutorial when in the medical ward. As for bugs, the only actually noticiable ones are crashes that I've had twice, after nearly six hours in both games. I get more crashes out of Paradox games. It's very solid work, considering the ambition (new Codex buzzword?) of the game.
Actually, the gameplay also seems to work out very well compared to other ARPGs, with the stealth element being genuinely above most of today and the golden age, along with a good for what it is combat (doesn't blow your mind, but doesn't blow either, just completely and utterly average).
A particular thing I'd point out is that you can't run during Shadow Operative (invisibility), since you still make sound. That Gametrailers clip was done on Easy and with a fully stealth-optimized armor. In fact, I for one have had many moments of gratefulness to invisibility, but far more to the one that removes movement noise.
As for the much debated dialogue system, it works well in action. Sure, it doesn't give you a damn clue of the final line, EXCEPT a very vital one: It's intended tone and purpose. This is very good, since you have the delightful opportunity to read up on NPCs before encountering them (sometimes), where it helps to know what kind of tone and actions they hate and like. That way, you can't have a sudden unexpected ninja result because you interpreted a dialogue choice different than the designer.
Also, CnC up the butt. Still investigating further on whether or not the story decisions carry actual weight and difference, or are primarily flavour. At the very least, it seems a lot of kill/not kill decisions and relationships with NPCs have far-reaching consequences, along with more immediate ones.
Oh yea, the writing is p. cool too. Not MotB, but then again it doesn't deal with such a scope and style as MotB where you can have monologues like Gann's fake birth story.
