I've never seen any tensions between PR's, and DR's in my neck of the woods, though most PR's here are very Americanized, they usually don;t even speak Spanish,and they're very few off the boat PR's. The small town I live in, was mainly PR during the 70's, and 80's, when the Dominicans started arriving in the early 80's there was some friction, according to what I've been told, but both groups got along for the most part. I know so many PR/DR couples, and many Half PR, Half DR people.