Personally I find it too cutesy, insubstatial and a bit dare I say it, downmarket. The only person I know with it is the actress
Lacey Turner. It's quite popular in the
UK at the moment though, along with a lot of other two syllable L names names e.g
Lexie,
Layla,
Lily,
Lola,
Lucy, etc.
I can't imagine it on a boy, even if it's technically a surname. I've also never seen
Lacy.