USA cheaper, but watch all the additional charges. The CDW and theft features are very expensive in Italy, and car breakins and theft are major issues country-wide, so it's good if you have a rate that includes those features. Hertz and Europcar have lots of US based discounts from AAA to Corporate ones that include some of those items. Other things remaining equal the smaller the car the better. Italian cities are crowded. Use a GPS if you can; you need it as does nearly everyone.