I did some testing with the new firmware that came out February 2017 and found the default sharpness setting to be ideal. Changing the sharpness to -1 may sacrifice details and should be avoided. Personally I would use +1 sharpness in bright lit conditions and use noise removal to get rid of some noise in the dark regions. Here is side by side comparison of different settings:

Really appreciate things like this. Good to see. Thanks for sharing!

Thanks for sharing. I got a better result after using 'sharpness 0' and add 2-3 percent sharpness in post processing (FCPX)