The Orbis is only half as big as the Segway that spawned it, but don't let that fool you. The thing's easily twice as cool, especially if you happen to be Woz playing Segway polo.
I mean come on. Facts are facts. Smaller footprint. Easier maneuverability in the tight spots. Folds down for easy storage in the closet when that hot date comes over for a digestif. Brisk 13 mph top speed. Completely portable. Battery powered. This is assuming, of course, you give two shits about the Segway to begin with.
Negatives? Balance issues abound, sure, but the designers can work those our with Woz's money help, right?