I played the demo yesterday. Damn that was fun. I probably shouldn't buy another game right now because I don't have a lot of money or free time, but I'm definitely weighing my options. I absolutely recommend everyone checking out the demo.
As for the limits, I think that's why it's a demo. They don't want you to start thinking of it as a replacement for the game itself. And, while they could have cut out the cut scenes, the last cut scene was the perfect teaser for "buy this game."