I'm glad I didn't pay to get into the Deering Estate. I'm a long-time MIami resident and went here about 15 years ago. The house itself is very modest compared to Deering's brother who owned Vizcaya towards downtown Miami. What was so disappointing was that the house was virtually empty of the family's furnishings and belongings. Most of the rooms had no furniture and they just left it completely empty.
Even the artwork had nothing to do with the family. They give art classes on the premises and it looked like some of it was done by their student, however it was random material. There was no sense of how the family lived in the house. There was supposed to be a tour at 3pm, however no one showed up for it. Even the nature trails were really devoid of any educational or historical perspective. For the $12 admission price I'd recommend going elsewhere.
It is a pretty place to bring a picnic lunch and sit and read, but if you're looking for history this is not the place.