I played around with it today and was very impressed. Tracking is much more accurate than I imagined, and the fact that it uses a lit ball means it works very well (even better, in fact) in the dark. The object (sword, baseball bat) and painting demos were very intuitive. The body tracking demo was interesting, but it needed a bit more work.
All in all, I came away very impressed and will definitely buy one of these this year.
What exactly did you try ?
Did they have the puppet/mecha out for attendees to "play" ?