I happen to live next door to a tax-credit affordable housing complex in Frisco. It was built two or three years ago, and I have seen no ill effects from it. Frankly, it looks more beautiful than the regular apartment complex I live in. This is why I was disappointed to see that the Frisco City Council rejected a call to support another affordable housing development: http://www.dallasnews.com/news/community-news/frisco/headlines/20150304-frisco-council-denies-support-to-affordable-housing-project.ece
A simple Google search brings up numerous studies, which show that there are no documented ill effects of affordable housing, with some studies showing positive effects. Here is just one of them: http://www.shelterforce.org/article/2891/fear_of_affordable_housing_perception_vs._reality/.