Very little configuration is needed to replicate all Salesforce data to a local SQL server. Custom objects added in Salesforce are automatically added as new tables in the replicated database. Custom fields added in Salesforce are automatically added as new columns in the replicated database.
Configuration files make it easy to configure replication, such as excluding certain objects, how often to replicate each object, etc.
Logs are very verbose. They can be very long, but when something isn't working right, they are very helpful in figuring out exactly what is causing the problem.
Records that are deleted in Salesforce stay in the replicated database forever.
Two way replication is easy. Records can be inserted or changed locally and uploaded to Salesforce simply by flagging the new or updated rows with an 'I' or 'U'. You can also delete records by flagging them with a 'D'.
Besides a browser based user interface, it also has a command line interface. Those familiar with the command line will appreciate the ability to run any task from the command line.
If a field type is changed in Salesforce (like from an integer to a text field), Relational Junction will not automatically change the column in the local database. Instead, the replication script will fail until the column is fixed. To do this, you have to delete the column, then run some commands to have Relational Junction add the column again with the correct data type.
If you just want raw data, RelationalJunction is easy to use and fully functional. If you need ETL tools, and the ability to manage what data gets replicated where, this tool will not do it for you.