I suspect that like almost everything, the results that you achieve with bi-wiring are system and taste dependent. I tried it with Castle Acoustic Isis speakers (already had the additional shotgun run after a failed bi-amp setup, so why not). Well, I preferred the sound of running a single cable and using a jumper (made from the same Kimber Kable) to that of the shotgun configuration. The bi-wire did give me increased separation of instruments, a lighter but more detailed midrange and additional bass response as well. The overall sound however did not seem as balanced and the crossover seemed to be more apparent in the mix as opposed to using the jumper. The sound obtained when using the jumper was more to my personal liking. Both ways sounded different. Other than my personal taste and preference it could have been my longer than normal cable runs, the crossover in the speakers (pretty high at 3500hz with a 12db per octave step) or who knows. If you have the extra cable or an internal bi-wire or can get one on loan, try it - you may like it.
