I originally wrote it in Spanish, my native language. My English is OK, but probably not as good as my Spanish, especially not when writing something that needs to "read nice" (as opposed to, say, technical articles).

I started translating it myself but the progress was too slow. I hired a translator, who was a native English speaker. The result is OK but not great -- in the end I could have done an equally good job. So I'll probably be writing the sequel in English.

To answer your question -- I believe the original Spanish version is slightly better.