I have an XBR4, the same used for the demo kiosks in the stores.
The reason things look so much better on the demo kiosk is probably because they have Vivid Mode on and MotionEnhancer turned up to high. The Vivid mode actually reduces detail, but the brightness hides this, and it burns the retinas when you get the tv in your house, but the ME does wonders. The ME creates transitional frames between each frame while in 24fps mode (120hz), giving films a much more fluid look. The only problem with this is that the "new" images the tv creates often artifact, especially on fast moving scenes. For example, when the camera pans over the Rohirrim army in LotR: the Rotk just as they begin to charge into the Orcs at the battle of the Pelennor field, the edges of the screen have major ghosting, and the middle of the image hs lot's of artifacting. However, slower moving scenes look truly 3d, especially on PotC.
Yes, I know LotR is an SD film, but it does wonders even for SD, making the battle of Osgiliath (the night ambush), for instance, look truly 3 dimensional.
The majority of the time I keep ME off as the artifacting bugs the crap out of my eyes. However, my friends love the stuff, and beg me to turn it on whenever they come over.