From what I understand, NBC only has 1 HD uplink in NYC and if there's problems with it, then those problems will be sent out to the entire country. For SD, they have a backup uplink in CA somewhere so if the NYC SD uplink has problems, they switch over. Now this doesn't mean every problem can be traced back to the NYC uplink since some report their local PQ is fine while others report theirs is terrible. In that case I would suspect the problem is with your local station. My Buffalo PQ looks great OTA - when I can get it.
