Has anyone tried the PhaseOne Demo?

I was researching the Phase One Digital Backs/bodies/setups and I was interested in knowing whether or not anyone has tried one of their demos, or what their experiences were with them. I'm really interested in learning the bottom line difference between their photos and photos that come from a high end Nikon DSLR. (Obviously higher resolution, larger files, raw, accurate color rendition, etc, but there's definitely an entirely different 'feel' to medium/large format photographs that are unattainable through smaller format [d]slrs.

http://www.phaseone.com/en/Try-and-buy.aspx

Thanks,
~Alton

Added (1). I feel that the PhaseOne camera system will also incorporate a wider dynamic range in a single shot, whereas you may have to bracket with another camera.
I also feel the answer below may potentially be misleading in that while you 'can' do the same thing with another camera, it just may take longer, be more complicated, or both, which discourages one from using it at all.

Basically, what you can do with one camera, you can do with another. It's just that working with larger formats will allow you to manipulate more detail if and when you want to.

No, I haven't "tried" the PhaseOne. I would be more than contented to have a Mamiya that goes down to ISO 50.