In my humble opinion, Dominicans are nicer when you are in jail, in hospital or dead. They are also nicer when you break down on the road and will help you change a tyre. They are friendlier in the street, and in shops and businesses when you know them.
However, they will appear to be nicer when they are lawyers, doctors, or when they think they can make money out of you. They are experts at being nice when they think that one day you can do something for them. Funnily enough, the richer or more powerful they think you are, the nicer they are to you.
For the first time visitor you think they are fantastic, what a friendly country. For the longer time expat, just be careful as this 'niceness', may hide an ulterior motive.
Having said that, the illusion of friendliness is much more pleasant than the reality of 'I don't give a ****ness' of other countries. Just know it for what it often is. Do not be deceived not naive.
Matilda