I think this is one of those very rare times a name can go either way. Honestly, I know a little boy and a little girl named Quinn and it suits both of them perfectly. I don't think of it as too masculine or too feminine, although I would pair it with a very gender-obvious mn.
My DH likes Rory for a boy, but I can't get past all the comments people make that it is for a girl when we mention it as one of our maybe names.