I don't really like
Harley or
Hadley. Neither sound feminine at all to me.
Harley sounds masculine if anything and
Hadley just sounds clunky and unattractive to me. I don't see the appeal. I do like
Harley more though. I know one
Harley that is a boy and a dog named
Harley too. It's a boy dog. Probably why I see it as masculine.