With E3 coming up, JohnGR pointed out a video in the comments of one of our E3 trailer posts that compares Ubisoft's demos with their released games. I tend to be relatively forgiving of these issues, personally, but the video is quite well done from an editing standpoint. It has quite a few moments of dry irony, especially with the contrast between the demo's busy audio sequences and the game section's silence.
We'll be seeing a lot of demos over the next handful of days. It's good to keep in mind that they are promotional snippets, either video or playable, that represent what the developer or publisher wants their game to be viewed as. Sometimes, it's just an overly optimistic view of what they can accomplish.