I thought the demo sucked actually. I liked original game and am looking forward to the Xbox version, but the demo killed some of my enthusiasm toward its impending release. The graphics were not impressive for an Xbox game and the controls were sloppy. I hate to say it, but I think that Rare needs to put more time into this one. However, as someone said, the SPR parts were not that great in the first game, and were a poor choice to promote Conker, so I'll try not to judge the whole game based on this demo.
I really don't know why so many of you are impressed with the graphics. To me, it looks maybe twice as good as the N64 version, with some added effects here and there, and the framerate is terrible. I've seen screen shots of other parts of the game though and they look much better than this demo. Maybe the demo is from a much older build? I'm keeping my fingers crossed that this is the case.