Fine, I've ordered with the american amazon several times and, it didn't take more than a week as long as you pay the extra fast delivery track, Books and Cds are not subject to custom fees in Argentina which makes all type of procedures ever lasting. (You want to deal as least as possible with Aduana in Argentina!) One warning: Don't order any electronics since they won't get passed customs.
I've tried with amazon.fr, bought some cds, and the new goncourt les bienveillantes by littleton and took ages. I wonder why the differences. Like months. I thought it was arriving by ship.