Network Analyst is a fun package to explore. It allows the calculation of much more meaningful distances than a buffer can accomplish. Of course with more power and potential comes more difficulty/buggyness and errors to be encountered. I was using ArcGIS’s Network Analyst (NA) extension to calculate the distance from residential blocks to various amenities using the ‘Find Closest Facility’ method. I was encountering significantly high failure rates – 90 percent of the blocks failed to find a facility.