I have a Plantronics Calisto B70 Bluetooth headset that came with Dragon Naturally Speaking (Amazon.com: Dragon NaturallySpeaking Premium 11 Bluetooth).
If I try using sound recorder, I can hear some crackling noise as well as my voice, so I don't think the quality is great.
One time, I was able to get it working 99% accurately with DNS, but since then I haven't been able to repeat that accuracy.
The headset is worse in Windows Speech Recognition, perhaps because it isn't tuned for Bluetooth like DNS is.
For what it's worth, I tried doing a sound recording using a couple other pairs of analog wired headphones, and there was noise present on those too, so I'm thinking wired USB headphones would be the best, but can't confirm that.
I just bought the Plantronics 625 USB headset.
Training Dragon Naturally Speaking seems to be working better than with the B70 Bluetooth.
I also tried recording my voice as a way to compare them. The B70 sounds OK, but has a small amount of hiss in the background and has a lower range of frequencies. The 625 sounds much clearer and more natural.
Here's the recordings if you'd like to compare for yourself.
You could also have a look at the Dragon Naturally Speaking Hardware Compatibility List.