Edén (the correct Spanish spelling) sounds [e'ðen] (eh-DHEN) and it is traditionally used for boys in Spanish speaking countries since long time ago; think about Edén Pastora
(the Comandante Cero), born in 1938. And that it is used as masculine name is not surprising because, not being linked with Marian
titles, the place name is masculine in Spanish (el Edén).
I think that the use of Edén as given name in Spanish predates the use of Eden
in English (and that is why is very surprising to a lot of Spanish speakers the use as girl name), mainly in some American countries where the Biblical names are very popular.
Perhaps the US Hispanics see Edén as a refreshing alternative to Efrén and that is why it suddenly growns up in popularity.
A Spanish respelling of the English pronunciation of Aidan
is Eidan, which is not unknown.