What do you like best?
SQL Developer is very useful to organize different connections (Oracle databases). It's easy to use, intuitive and clean design. It has plenty plugin users.
In terms of SQL developing it's a tool that offers the developer everything needed.
What do you dislike?
Quite slow and not so useful if you are not using an Oracle Database.
If you want to edit a table the process is not so quick as it should.
It has to improve some export tools (Excel tables, e-mail connection).
Recommendations to others considering the product
If you are starting with SQL, SQL Developer is good starting point.
If you are using for professional purposes, more advanced level, the tool gives a lot and almost everything needed and it's free.
What business problems are you solving with the product? What benefits have you realized?
To develop the application I am working on at the moment, I need to get information and cross it with different databases. SQL does the job.
I also use it to Data management of different applications.