I tried it - it really works (start BB FIT in pairing mode, take out the BT dongle from Voyager Legend and put it back in again).

However, only mono (telephone quality) comes through and since I use an office notebook (without admin rights) I cannot say whether this can really be changed. According to the product sheet, the Voyager Legend supports A2DP, i.e. stereo - in the audio settings of the BT dongle, I find the format "1 Channel, 16 Bit, 16,000Hz" preset and greyed out; it is possible that a stereo format can be selected if you have the system permissions.