I dislike it, mostly for being a male name in drag but mostly for its resemblance to
Cindy. A lifetime of fielding the same questions (Is it a boy or a girl? Did you say
Sydney or
Cindy? Is that short for something? Is your name really
Cynthia?) would seem very long.
I know a
Jennifer Sidney whose mn is the same as her father's. I suppose that's OK. At least she never has to use it.