Granada seemed pretty intensely Americanized to me when I went earlier in the year. (And Americanized with some pretty non-adventurous tourists; the other American tourists at my hotel were appalled to learn that I'd been taking public transportation and not participating in packaged tours.) The rest of the country, less so; most of the tourists I ran into outside of Granada were European or Canadian. But there were no shortage of tourists anywhere--every single person on the chicken bus I took from Rivas to Granada, for example, was a tourist. (Excepting the driver, of course!)

Oh, to answer tcormier's question, everyone I met preferred $, but of course paying in $ makes it harder to bargain for small items, and any prices will obviously get rounded up to the nearest dollar or five.