Spanish speaking people out there

Yes. In fact, I think Odette is fluent in Spanish, but was "faking" an Americanized accent whenever she "attempted" it. The Spanish from the native speakers made complete sense, even the mumbling woman that was giving them directions to the hotel.

Yes, they talk true spanish. Even the "mumbling woman" mentioned above. You have to take in mind that Argentina is a very large country and, like happens in every other countries, there are different regional accents. That woman sounds typically from deep north west.
About the movie itself, this remake has nothing to do with the original, which I recommend to watch.