Vacancy Rates on NeighborhoodScout

[Alexander Spira]

I recently came upon this site called Neighborhood Scout. www.neighborhoodscout.com. It has tons of information about the CT and NJ areas where I am looking to buy. One of the most helpful features is that it breaks down a area by the neighborhood. For example New Haven CT is a large area that spans miles and Neighborhoodscout breaks it down in to 20 smaller areas giving a much easier understanding of where to look and how to gauge correct comps because a few blocks can make a big a price difference. Does anybody have a opinion about Neighborhoodscouts accuracy ? 

They also tell you the average vacancy rate of that area. I see they say West Haven has a vacancy rate of 9.2%. Does anybody have any experience with this area, is that accurate ? Also in general how do people gauge a vacancy rate ? Thanks in advance to everyone.