If you are in the 5 boroughs and subscribe to one of these services, please advice which one you have any how you like it. I plan to join one of these soon.
BNN by far. Their service provides 24/7/365 coverage, with a full time paid staff and they're fast and accurate. The other services are all part time "fur fun" people with no guarantee you'll get anything for the city at any given time. BNN also has solid customer and tech support.