I would give a seven or eight for usability. I agree that the Harry Potter character isn't the best namesake, but in reality, compared to what some parents use nowadays, that's nothing. If it were me, I would choose any literary connection over the terribly trendy and horribly spelled Madysynn or Skyylynn.
Yes, I actually do know someone who has used the latter...
EDIT: I forgot to mention that it is a constellation is addition to being a literary character. =)
This message was edited 6/27/2011, 8:08 AM