As far as section 8, not all tenants who receive section 8 are rowdy. I have rented to section 8 tenants and found them to be the best while others...well...not so much.
I think going by the building at night and just watching the residents will tell you what you need to know. Many people make the mistake of deciding upon a place without analyzing the night traffic and are surprised when they spend their first night.
Realtors can't give you an honest answer on this one because they are not allowed to.