Moved here in January from Northern Virginia and i really like it for the most part. I have found that people are people where-ever you go. There were a-holes in VA, there are a-holes here. Take what you like and leave the rest.
As far as areas go, East of Miller Place, Rocky Pt., it seems very rural to me - vineyards etc., pretty but a bit more isolated. I really like Smithtown, Northport, and the Three Villages area. Rockville Center is very nice also but seemed quite congested and more "city" to me. The areas I mentioned have more of a town or village ambience but all of the amenitites that you would want like nice restaurants, good shopping, activities etc... seem to be plenty. I don't have kids so can't speak to the schools.
I have found NY'rs can be a bit more abrupt, but I find the humor in it and for the most part it's not personal. I have also met a lot of very friendly warm people here. Good Luck!