The Jabra Biz 2400 II is exactly what I had in mind when I brought up the relatively premium "call centre grade" headset mics.  I have the monaural USB version (Jabra 2496-829-309), which currently sells for ~US$200.  It is not as comfortable as either the binaural Sennheiser SC260 or the binaural MB Pro2.  But it is the best headset for my voice by my own objective testing.  

Biz 2400 II is for me appreciably more accurate than SC260, and considerably more accurate than MB Pro2.  FWIW the first headset I tried was the CA$50 Plantronics Blackwire C3210 - definitely subpar.  It would seem to me then when it comes to "call centre headsets" at least, price gradient reasonably separates out quality.

I did not specifically test the noise-cancelling oomph of Biz 2400 II in a hostile environment.  But given its selling point, it would hardly suprise me that folks are getting good mileage in loud places.  In fact our hospital Call Centre agents use these.  So its telephone and VoIP qualities are high, too.

Some side observations from me based on others' forum feeback: FlexyMike DEC is considered super sensitive, i.e., "hot", on its own.  Thus it should handle soft voice superbly.  Audio-Technica Pro 8HEmW is rather the "opposite" and quite insensitive, thus reckoned to be advantageous in loud places - but it requires you to speak a louder voice into it.  Neither has any "active noise cancellation".  

Is either above better than the Biz 2400 II or the Boom O in meeting OP's requirement?  Who could know with certainty without testing and head-to-head comparison?

Anyway, back to the Biz 2400 II mono, the extendable part of the headband is rather short.  If I had to buy it again, I'd go with the binaural version.

Currently I use mine mainly for VoIP calls.  But I could use it for Dragon without much concern.  However, when I am by myself at home or in the office, I am kind of in the MDH camp as in finding that an unencumbered, close-talk "table mike" style of setup is still the most ergonomic.

That SpeechWare TwistMike in fact still interests me.  My current "steampunk" setup is a bit too "in your face" for when we receive patients back into the office (I use an AT2005usb in the office, mounted on the same Lamicall LS05 gooseneck).  The TwistMike would look decidedly less over-the-top.

P.S., it seems as though the Biz 2400 II comes in variants that are either "medium-noise-cancelling" (e.g., the one I have) or "ultra-noise-cancelling", with a few other permutations thrown in, plus a bunch of marketing buzzwords.  Such is the state of things.