Come to think of it, I really did need the geocoding.
There is a problem with apartment buildings where on one lot you have 2 buildings with different addresses, but they're really the same. So I counted as possible dupes to review any two that were close. (I used "within adjacent 100' by 100' boxes, so that range was 100-300 feet.) That I couldn't have done without geocoding, but it was only a nice to have anyways. And it obviously doesn't apply in this case.
Cheers,
Ben