That's a pretty amazing bass, but as a bassist myself, I think 11 strings is overkill. With that many strings so close together, the bass becomes a tapping (as opposed to plucking/slapping) instrument, as seen in the vid. Maybe it's just because my tapping's subpar, but I think having that many strings would take some of the fun out of playing bass.
RELATED:
Super Mario Theme on an unplugged 12-string bass: http://www.youtube.com/watch?v=AyLPeRZAOho&mode=related&search=
12 String Bass (From Dean, gotta love 'em!): http://www.youtube.com/watch?v=Umw3LGc0keM&mode=related&search=