I have recently used this feature and it was awesome. The only problem I have encountered to save the json data in file.
The output of json was large and when I tried to copy the data SQL doesn't allow me to copy. I follow the below steps:
Tools --> Options --> Query Results --> SQL Server --> Results to Text --> Maximum number of characters displayed in each column
Tools --> Options --> Results --> Maximum characters per column
After applying the above steps I was unable to save the data.
I tried to save the output by right clicking and save the data as file, but this break the json and when I validate it it failed and said - the document is not json format.
Then I used SSIS script task to use SQL query as a source to generate the output and save the results as .json. Which was perfect json.
Deepak Kumar Sharma