That's totally fine Nathalie
I recently got to watch the English version too, and... I was surprised by how much Spanish there was. I knew there would be some words, like I saw in trailers, but I do think they overdid it (and sometimes quite unnecessarily xP). I guess that way it's more appealing for American audiences who sometimes hear it from co-workers and such, but I can understand why it must've been distracting for people who aren't used to hear it, like in most of Europe.
I wish they had kept it to a minimum like, say, Beauty and the Beast with French, but oh well >< at least I got to enjoy the full totally-not-weird Spanish version, and nothing's gonna take that from me
The cast is mostly different from the English version except for Gael García Bernal who reprised his role as Hector. Some other side characters also used the same actors, but I don't remember who exactly.
I think it's better that way, since it keeps the accents more authentic. Besides, I do think Miguel's singing is much better in Spanish, but that's just my biased Mexican opinion