Pardon my ingnorance and cynical disposition, but apart from the compelling surreal 'storyline' (which in the end has a hard time going somewhere), what is so great about the demo?
Yes, it's small, but farbrausch always was good at procedural textures, so no points there.
It looks nice, but hey, we're talking a heavy DirectX9-based application here powered by a not-so-slow CPU. That's like being amazed over a car that can break the sound barrier, and then learning it is powered by two jet fighter engines. Definitely far from easy to control, but once you do, well, 'obvious'. This means that a lot of 'wow'-factor is actually in the design of the demo, but:
There's tons and tons of little cubes and prisms flying over the screen (requiring streamlined coding), the lighting is done with attention to detail (espcecially the fence in the beginning, and the reflected sheen when the cubes pass a noticable distance in front of a window), and the volumetric shading near the end gets a thumbs up. But apart from that, it could have been a playable game demo, where these things also pop up from time to time. So what is its 'wow'-factor?
I'll concede: it looks nice, and the beginning, where the city is being run over, is captivating. But 'the best ever'? Certainly not. I think farbrausch's earlier 64k-efforts are better, despite their limitations from the underlying DirectX API. 3D Mark 2001, 2003 and 2005 have beautiful landscape scenes which make this demo look drab, blocky and very mathematical in comparison.