For inner-city short trips, this bicycle design based on the simple unicycle provides much convenience: compactness, quick turns, chain-less, grease-less mechanism for minimal maintenance, fast stop-and-go reactions, and rear-wheel power for going over curbs. It's all about making a quick dash to neighborhood establishments.
The design is an achievement both aesthetically and conceptually. I'd love to try one out to test its functionality; I suspect it would take a little getting used to, but I'm sure the quick turns and its ability to wiggle through tight spaces would be very satisfying.
The simplicity of the design reminds me of simpler bikes from days long past, as if the quest for self-powered, wheeled transportation has come full-circle with this bike, but with all the benefits of hind-sight.