I've used Amazon Spain twice, and they work very much like Amazon USA regarding everything.
Last year, I purchased some pet supplies as a gift for one of my brothers, who lives in Spain, and the experience was excellent. Some of the products advertised were not available on Amazon Es, and were supplied by external European shops; however, the time of delivery was clearly mentioned on the item page, so I knew that beforehand; yet, the item arrived well before the estimate delivery time.
The second time, I ordered two items for my elderly mother during my
holidays there. Items were dispatched separately the next day, and I
received them at my doorstep two days later.
They have a huge selection of products and terrific prices and I can honestly say that they provide better service and range of products than Amazon Au.
I will certainly buy from them again!