Yes, frequency of 1000 gets 16GH/s on a 16 chip board.
That's perfect. It seems that you did it right. Now what's left is to optimize your heatsinks, and you could go up to 1.6 - 1.7GH/s per chip.
I wasn't sure if you were talking about using the MCP9700A to take that measurement for reference or building it into your design.
These chips are inexpensive so I was thinking about building them into my design to replace the thermistor. Though the sensors are accurate, given the above considerations, their measurement would be only good for the purposes of thermal shutdown and some rough monitoring of the module condition. Perhaps the performance of forced air cooling system could be also evaluated based on this sensor data. I'm going to integrate several boards into a rackmount case, and there I'd need to take care of aerodynamics, fan locations, etc.