I read a post from Ray Kimber on the subject of bi-wiring at audioasylum.com and he seemed to think that the back EMF voltage generated by the woofer(s) in some systems was a large enough factor to make bi-wiring preferable in some but not all models of speakers. From all the posts I've read on the subject this morning (quite a few) the consensus appears to be that bi-wiring can result in worthwhile performance gains in many, but not all, speakers. The bottom line is that you really need to try it in your own system and hear the differences for yourself.
Because of the predominant sentiment, that bi-wiring is prefered by many B&W owners, I removed the straps and bi-wired my CDM 9NTs this morning. I used my shotgun run of InnerSound speaker cable on my mid/tweeter section, as I had been, and a pair of AudioQuest Hyperlitz IV for the bass section. My immediate impression of this hookup was quite favorable and after a few hours of listening to different cuts that impression has only gotten stronger. The sound seems cleaner, smoother, and more coherent. And with the strapped single-wired configuration the midbass was fatter and less defined, whereas the bi-wire seemed to make the bass better controlled and possibly more extended -- to my ears it sounds more correct. I believe I'll adopt the bi-wire permanently for the 9NTs.